<?xml version="1.0" encoding="us-ascii" standalone="yes"?>
<!-- RRD ActiveDisclosure(SM) XBRL Linkbase Document - http://www.financial.rrd.com/ -->
<!-- Creation Date      : 2015-05-11T18:14:25.2881381+00:00 -->
<!-- Version            : 2.0.5.0 -->
<!-- Package ID         : 4A01AB50998B740AE962489C976401FA-0000879407-001503 -->
<!-- Copyright (c) 2015 R. R. Donnelley & Sons Company. All Rights Reserved. -->
<linkbase xmlns="http://www.xbrl.org/2003/linkbase" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/role/TemplateLink" xlink:href="arwr-20150331.xsd#TemplateLink" xlink:type="simple" />
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/DocumentDocumentAndEntityInformation" xlink:href="arwr-20150331.xsd#Role_DocumentDocumentAndEntityInformation" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/DocumentDocumentAndEntityInformation">
    <loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityCommonStockSharesOutstanding" xlink:type="locator" xlink:label="dei_EntityCommonStockSharesOutstanding" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityFilerCategory" xlink:type="locator" xlink:label="dei_EntityFilerCategory" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_CurrentFiscalYearEndDate" xlink:type="locator" xlink:label="dei_CurrentFiscalYearEndDate" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityCentralIndexKey" xlink:type="locator" xlink:label="dei_EntityCentralIndexKey" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityRegistrantName" xlink:type="locator" xlink:label="dei_EntityRegistrantName" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_TradingSymbol" xlink:type="locator" xlink:label="dei_TradingSymbol" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentFiscalPeriodFocus" xlink:type="locator" xlink:label="dei_DocumentFiscalPeriodFocus" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentFiscalYearFocus" xlink:type="locator" xlink:label="dei_DocumentFiscalYearFocus" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentPeriodEndDate" xlink:type="locator" xlink:label="dei_DocumentPeriodEndDate" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_AmendmentFlag" xlink:type="locator" xlink:label="dei_AmendmentFlag" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentType" xlink:type="locator" xlink:label="dei_DocumentType" />
    <loc xlink:href="arwr-20150331.xsd#arwr_DocumentAndEntityInformationAbstract" xlink:type="locator" xlink:label="arwr_DocumentAndEntityInformationAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_DocumentAndEntityInformationAbstract" xlink:to="dei_DocumentType" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_DocumentAndEntityInformationAbstract" xlink:to="dei_AmendmentFlag" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_DocumentAndEntityInformationAbstract" xlink:to="dei_DocumentPeriodEndDate" order="10130.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_DocumentAndEntityInformationAbstract" xlink:to="dei_DocumentFiscalYearFocus" order="10190.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_DocumentAndEntityInformationAbstract" xlink:to="dei_DocumentFiscalPeriodFocus" order="10250.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_DocumentAndEntityInformationAbstract" xlink:to="dei_TradingSymbol" order="10310.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_DocumentAndEntityInformationAbstract" xlink:to="dei_EntityRegistrantName" order="10370.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_DocumentAndEntityInformationAbstract" xlink:to="dei_EntityCentralIndexKey" order="10430.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_DocumentAndEntityInformationAbstract" xlink:to="dei_CurrentFiscalYearEndDate" order="10490.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_DocumentAndEntityInformationAbstract" xlink:to="dei_EntityFilerCategory" order="10550.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_DocumentAndEntityInformationAbstract" xlink:to="dei_EntityCommonStockSharesOutstanding" order="10610.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/StatementConsolidatedBalanceSheets" xlink:href="arwr-20150331.xsd#Role_StatementConsolidatedBalanceSheets" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/StatementConsolidatedBalanceSheets">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:type="locator" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:type="locator" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_MinorityInterest" xlink:type="locator" xlink:label="us-gaap_MinorityInterest" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockholdersEquity" xlink:type="locator" xlink:label="us-gaap_StockholdersEquity" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:type="locator" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:type="locator" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AdditionalPaidInCapital" xlink:type="locator" xlink:label="us-gaap_AdditionalPaidInCapital" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CommonStockValue" xlink:type="locator" xlink:label="us-gaap_CommonStockValue" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PreferredStockValue" xlink:type="locator" xlink:label="us-gaap_PreferredStockValue" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockholdersEquityAbstract" xlink:type="locator" xlink:label="us-gaap_StockholdersEquityAbstract" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract" xlink:type="locator" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CommitmentsAndContingencies" xlink:type="locator" xlink:label="us-gaap_CommitmentsAndContingencies" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LiabilitiesNoncurrent" xlink:type="locator" xlink:label="us-gaap_LiabilitiesNoncurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OtherLiabilitiesNoncurrent" xlink:type="locator" xlink:label="us-gaap_OtherLiabilitiesNoncurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability" xlink:type="locator" xlink:label="us-gaap_BusinessCombinationContingentConsiderationLiability" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CapitalLeaseObligationsNoncurrent" xlink:type="locator" xlink:label="us-gaap_CapitalLeaseObligationsNoncurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LiabilitiesNoncurrentAbstract" xlink:type="locator" xlink:label="us-gaap_LiabilitiesNoncurrentAbstract" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LiabilitiesCurrent" xlink:type="locator" xlink:label="us-gaap_LiabilitiesCurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OtherLiabilitiesCurrent" xlink:type="locator" xlink:label="us-gaap_OtherLiabilitiesCurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NotesPayableCurrent" xlink:type="locator" xlink:label="us-gaap_NotesPayableCurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CapitalLeaseObligationsCurrent" xlink:type="locator" xlink:label="us-gaap_CapitalLeaseObligationsCurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DerivativeLiabilitiesCurrent" xlink:type="locator" xlink:label="us-gaap_DerivativeLiabilitiesCurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DeferredRevenueCurrent" xlink:type="locator" xlink:label="us-gaap_DeferredRevenueCurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_EmployeeRelatedLiabilitiesCurrent" xlink:type="locator" xlink:label="us-gaap_EmployeeRelatedLiabilitiesCurrent" />
    <loc xlink:href="arwr-20150331.xsd#arwr_AssetAcquisitionAccruedPurchasePricePayable" xlink:type="locator" xlink:label="arwr_AssetAcquisitionAccruedPurchasePricePayable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AccruedLiabilitiesCurrent" xlink:type="locator" xlink:label="us-gaap_AccruedLiabilitiesCurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AccountsPayableCurrent" xlink:type="locator" xlink:label="us-gaap_AccountsPayableCurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LiabilitiesCurrentAbstract" xlink:type="locator" xlink:label="us-gaap_LiabilitiesCurrentAbstract" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:type="locator" xlink:label="us-gaap_LiabilitiesAndStockholdersEquityAbstract" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_Assets" xlink:type="locator" xlink:label="us-gaap_Assets" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OtherAssetsMiscellaneousNoncurrent" xlink:type="locator" xlink:label="us-gaap_OtherAssetsMiscellaneousNoncurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_HeldToMaturitySecuritiesNoncurrent" xlink:type="locator" xlink:label="us-gaap_HeldToMaturitySecuritiesNoncurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:type="locator" xlink:label="us-gaap_IntangibleAssetsNetExcludingGoodwill" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:type="locator" xlink:label="us-gaap_PropertyPlantAndEquipmentNet" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AssetsCurrent" xlink:type="locator" xlink:label="us-gaap_AssetsCurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_HeldToMaturitySecuritiesCurrent" xlink:type="locator" xlink:label="us-gaap_HeldToMaturitySecuritiesCurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OtherAssetsCurrent" xlink:type="locator" xlink:label="us-gaap_OtherAssetsCurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PrepaidExpenseCurrent" xlink:type="locator" xlink:label="us-gaap_PrepaidExpenseCurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:type="locator" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AssetsCurrentAbstract" xlink:type="locator" xlink:label="us-gaap_AssetsCurrentAbstract" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AssetsAbstract" xlink:type="locator" xlink:label="us-gaap_AssetsAbstract" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StatementOfFinancialPositionAbstract" xlink:type="locator" xlink:label="us-gaap_StatementOfFinancialPositionAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_AssetsAbstract" order="10330.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAbstract" xlink:to="us-gaap_AssetsCurrentAbstract" order="10410.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsCurrentAbstract" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue" order="10490.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:to="us-gaap_PrepaidExpenseCurrent" order="10570.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:to="us-gaap_OtherAssetsCurrent" order="10650.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:to="us-gaap_HeldToMaturitySecuritiesCurrent" order="10730.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:to="us-gaap_AssetsCurrent" order="10810.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAbstract" xlink:to="us-gaap_PropertyPlantAndEquipmentNet" order="10890.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAbstract" xlink:to="us-gaap_IntangibleAssetsNetExcludingGoodwill" order="10970.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAbstract" xlink:to="us-gaap_HeldToMaturitySecuritiesNoncurrent" order="11050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAbstract" xlink:to="us-gaap_OtherAssetsMiscellaneousNoncurrent" order="11130.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAbstract" xlink:to="us-gaap_Assets" order="11210.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_LiabilitiesAndStockholdersEquityAbstract" order="11290.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="us-gaap_LiabilitiesCurrentAbstract" order="11370.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_AccountsPayableCurrent" order="11450.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_AccruedLiabilitiesCurrent" order="11530.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="arwr_AssetAcquisitionAccruedPurchasePricePayable" order="11610.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_EmployeeRelatedLiabilitiesCurrent" order="11670.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_DeferredRevenueCurrent" order="11750.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_DerivativeLiabilitiesCurrent" order="11830.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_CapitalLeaseObligationsCurrent" order="11910.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_NotesPayableCurrent" order="11990.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_OtherLiabilitiesCurrent" order="12050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_LiabilitiesCurrent" order="12130.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="us-gaap_LiabilitiesNoncurrentAbstract" order="12210.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesNoncurrentAbstract" xlink:to="us-gaap_CapitalLeaseObligationsNoncurrent" order="12290.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesNoncurrentAbstract" xlink:to="us-gaap_BusinessCombinationContingentConsiderationLiability" order="12370.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesNoncurrentAbstract" xlink:to="us-gaap_OtherLiabilitiesNoncurrent" order="12450.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesNoncurrentAbstract" xlink:to="us-gaap_LiabilitiesNoncurrent" order="12530.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="us-gaap_CommitmentsAndContingencies" order="12610.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract" order="12690.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract" xlink:to="us-gaap_StockholdersEquityAbstract" order="12770.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StockholdersEquityAbstract" xlink:to="us-gaap_PreferredStockValue" order="12850.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StockholdersEquityAbstract" xlink:to="us-gaap_CommonStockValue" order="12930.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StockholdersEquityAbstract" xlink:to="us-gaap_AdditionalPaidInCapital" order="13010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StockholdersEquityAbstract" xlink:to="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" order="13090.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StockholdersEquityAbstract" xlink:to="us-gaap_RetainedEarningsAccumulatedDeficit" order="13150.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StockholdersEquityAbstract" xlink:to="us-gaap_StockholdersEquity" order="13230.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract" xlink:to="us-gaap_MinorityInterest" order="13310.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract" xlink:to="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" order="13390.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="us-gaap_LiabilitiesAndStockholdersEquity" order="13470.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/StatementConsolidatedBalanceSheetsParenthetical" xlink:href="arwr-20150331.xsd#Role_StatementConsolidatedBalanceSheetsParenthetical" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/StatementConsolidatedBalanceSheetsParenthetical">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CommonStockSharesOutstanding" xlink:type="locator" xlink:label="us-gaap_CommonStockSharesOutstanding" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CommonStockSharesIssued" xlink:type="locator" xlink:label="us-gaap_CommonStockSharesIssued" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CommonStockSharesAuthorized" xlink:type="locator" xlink:label="us-gaap_CommonStockSharesAuthorized" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CommonStockParOrStatedValuePerShare" xlink:type="locator" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PreferredStockSharesOutstanding" xlink:type="locator" xlink:label="us-gaap_PreferredStockSharesOutstanding" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PreferredStockSharesIssued" xlink:type="locator" xlink:label="us-gaap_PreferredStockSharesIssued" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PreferredStockSharesAuthorized" xlink:type="locator" xlink:label="us-gaap_PreferredStockSharesAuthorized" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PreferredStockParOrStatedValuePerShare" xlink:type="locator" xlink:label="us-gaap_PreferredStockParOrStatedValuePerShare" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StatementOfFinancialPositionAbstract" xlink:type="locator" xlink:label="us-gaap_StatementOfFinancialPositionAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_PreferredStockParOrStatedValuePerShare" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_PreferredStockSharesAuthorized" order="10090.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_PreferredStockSharesIssued" order="10170.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_PreferredStockSharesOutstanding" order="10250.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_CommonStockParOrStatedValuePerShare" order="10330.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_CommonStockSharesAuthorized" order="10410.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_CommonStockSharesIssued" order="10490.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_CommonStockSharesOutstanding" order="10570.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/StatementConsolidatedStatementsOfOperationsUnaudited" xlink:href="arwr-20150331.xsd#Role_StatementConsolidatedStatementsOfOperationsUnaudited" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/StatementConsolidatedStatementsOfOperationsUnaudited">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTax" xlink:type="locator" xlink:label="us-gaap_ComprehensiveIncomeNetOfTax" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax" xlink:type="locator" xlink:label="us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTaxAbstract" xlink:type="locator" xlink:label="us-gaap_ComprehensiveIncomeNetOfTaxAbstract" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted" xlink:type="locator" xlink:label="us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_EarningsPerShareBasicAndDiluted" xlink:type="locator" xlink:label="us-gaap_EarningsPerShareBasicAndDiluted" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NetIncomeLoss" xlink:type="locator" xlink:label="us-gaap_NetIncomeLoss" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest" xlink:type="locator" xlink:label="us-gaap_NetIncomeLossAttributableToNoncontrollingInterest" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ProfitLoss" xlink:type="locator" xlink:label="us-gaap_ProfitLoss" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:type="locator" xlink:label="us-gaap_IncomeTaxExpenseBenefit" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:type="locator" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NonoperatingIncomeExpense" xlink:type="locator" xlink:label="us-gaap_NonoperatingIncomeExpense" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OtherNonoperatingIncomeExpense" xlink:type="locator" xlink:label="us-gaap_OtherNonoperatingIncomeExpense" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_UnrealizedGainLossOnDerivatives" xlink:type="locator" xlink:label="us-gaap_UnrealizedGainLossOnDerivatives" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_InterestIncomeExpenseNonoperatingNet" xlink:type="locator" xlink:label="us-gaap_InterestIncomeExpenseNonoperatingNet" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_GainLossOnSaleOfPropertyPlantEquipment" xlink:type="locator" xlink:label="us-gaap_GainLossOnSaleOfPropertyPlantEquipment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IncomeLossFromEquityMethodInvestments" xlink:type="locator" xlink:label="us-gaap_IncomeLossFromEquityMethodInvestments" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NonoperatingIncomeExpenseAbstract" xlink:type="locator" xlink:label="us-gaap_NonoperatingIncomeExpenseAbstract" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:type="locator" xlink:label="us-gaap_OperatingIncomeLoss" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OperatingExpenses" xlink:type="locator" xlink:label="us-gaap_OperatingExpenses" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DepreciationAndAmortization" xlink:type="locator" xlink:label="us-gaap_DepreciationAndAmortization" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensation" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensation" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_GeneralAndAdministrativeExpense" xlink:type="locator" xlink:label="us-gaap_GeneralAndAdministrativeExpense" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LaborAndRelatedExpense" xlink:type="locator" xlink:label="us-gaap_LaborAndRelatedExpense" />
    <loc xlink:href="arwr-20150331.xsd#arwr_AcquiredInProcessResearchAndDevelopment" xlink:type="locator" xlink:label="arwr_AcquiredInProcessResearchAndDevelopment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ResearchAndDevelopmentExpense" xlink:type="locator" xlink:label="us-gaap_ResearchAndDevelopmentExpense" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OperatingExpensesAbstract" xlink:type="locator" xlink:label="us-gaap_OperatingExpensesAbstract" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_Revenues" xlink:type="locator" xlink:label="us-gaap_Revenues" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IncomeStatementAbstract" xlink:type="locator" xlink:label="us-gaap_IncomeStatementAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_Revenues" order="10200.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_OperatingExpensesAbstract" order="10360.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingExpensesAbstract" xlink:to="us-gaap_ResearchAndDevelopmentExpense" order="10520.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingExpensesAbstract" xlink:to="arwr_AcquiredInProcessResearchAndDevelopment" order="10680.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingExpensesAbstract" xlink:to="us-gaap_LaborAndRelatedExpense" order="10800.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingExpensesAbstract" xlink:to="us-gaap_GeneralAndAdministrativeExpense" order="10960.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingExpensesAbstract" xlink:to="us-gaap_ShareBasedCompensation" order="11120.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingExpensesAbstract" xlink:to="us-gaap_DepreciationAndAmortization" order="11280.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingExpensesAbstract" xlink:to="us-gaap_OperatingExpenses" order="11440.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingExpensesAbstract" xlink:to="us-gaap_OperatingIncomeLoss" order="11600.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_NonoperatingIncomeExpenseAbstract" order="11760.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="us-gaap_IncomeLossFromEquityMethodInvestments" order="11920.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="us-gaap_GainLossOnSaleOfPropertyPlantEquipment" order="12040.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="us-gaap_InterestIncomeExpenseNonoperatingNet" order="12200.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="us-gaap_UnrealizedGainLossOnDerivatives" order="12360.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="us-gaap_OtherNonoperatingIncomeExpense" order="12520.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="us-gaap_NonoperatingIncomeExpense" order="12680.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" order="12840.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_IncomeTaxExpenseBenefit" order="13000.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_ProfitLoss" order="13080.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_NetIncomeLossAttributableToNoncontrollingInterest" order="13240.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_NetIncomeLoss" order="13360.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_EarningsPerShareBasicAndDiluted" order="13520.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted" order="13680.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_ComprehensiveIncomeNetOfTaxAbstract" order="13840.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ComprehensiveIncomeNetOfTaxAbstract" xlink:to="us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax" order="14000.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ComprehensiveIncomeNetOfTaxAbstract" xlink:to="us-gaap_ComprehensiveIncomeNetOfTax" order="14120.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/StatementConsolidatedStatementOfStockholdersEquityUnaudited" xlink:href="arwr-20150331.xsd#Role_StatementConsolidatedStatementOfStockholdersEquityUnaudited" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/StatementConsolidatedStatementOfStockholdersEquityUnaudited">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax" xlink:type="locator" xlink:label="us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SharesIssued" xlink:type="locator" xlink:label="us-gaap_SharesIssued_li0l2" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:type="locator" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_li0l2" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ProfitLoss" xlink:type="locator" xlink:label="us-gaap_ProfitLoss" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:type="locator" xlink:label="us-gaap_OtherComprehensiveIncomeLossNetOfTax" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross" xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross" xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NoncontrollingInterestDecreaseFromDeconsolidation" xlink:type="locator" xlink:label="us-gaap_NoncontrollingInterestDecreaseFromDeconsolidation" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesConversionOfUnits" xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodSharesConversionOfUnits" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueConversionOfUnits" xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodValueConversionOfUnits" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax" xlink:type="locator" xlink:label="us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodSharesNewIssues" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodValueNewIssues" />
    <loc xlink:href="arwr-20150331.xsd#arwr_ExchangeRightsExercisedDuringPeriodShares" xlink:type="locator" xlink:label="arwr_ExchangeRightsExercisedDuringPeriodShares" />
    <loc xlink:href="arwr-20150331.xsd#arwr_ExchangeRightsExercisedDuringPeriodValue" xlink:type="locator" xlink:label="arwr_ExchangeRightsExercisedDuringPeriodValue" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:type="locator" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised" xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised" />
    <loc xlink:href="arwr-20150331.xsd#arwr_StockIssuedDuringPeriodSharesExerciseOfWarrants" xlink:type="locator" xlink:label="arwr_StockIssuedDuringPeriodSharesExerciseOfWarrants" />
    <loc xlink:href="arwr-20150331.xsd#arwr_StockIssuedDuringPeriodValueExerciseOfWarrants" xlink:type="locator" xlink:label="arwr_StockIssuedDuringPeriodValueExerciseOfWarrants" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SharesIssued" xlink:type="locator" xlink:label="us-gaap_SharesIssued" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:type="locator" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StatementLineItems" xlink:type="locator" xlink:label="us-gaap_StatementLineItems" />
    <loc xlink:href="arwr-20150331.xsd#arwr_IssuedToNovartisAtSevenDollarAndFiftyThreeCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedToNovartisAtSevenDollarAndFiftyThreeCentsPerShareMember" />
    <loc xlink:href="arwr-20150331.xsd#arwr_IssuedToGallowayMember" xlink:type="locator" xlink:label="arwr_IssuedToGallowayMember" />
    <loc xlink:href="arwr-20150331.xsd#arwr_PreferredStockIssuedAtThousandDollarPerShareMember" xlink:type="locator" xlink:label="arwr_PreferredStockIssuedAtThousandDollarPerShareMember" />
    <loc xlink:href="arwr-20150331.xsd#arwr_IssuedAtEighteenDollarAndNinetyFiveCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtEighteenDollarAndNinetyFiveCentsPerShareMember" />
    <loc xlink:href="arwr-20150331.xsd#arwr_IssuedAtFiveDollarAndEightySixCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtFiveDollarAndEightySixCentsPerShareMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:type="locator" xlink:label="us-gaap_ClassOfStockDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:type="locator" xlink:label="us-gaap_StatementClassOfStockAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NoncontrollingInterestMember" xlink:type="locator" xlink:label="us-gaap_NoncontrollingInterestMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AccumulatedDeficitDuringDevelopmentStageMember" xlink:type="locator" xlink:label="us-gaap_AccumulatedDeficitDuringDevelopmentStageMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:type="locator" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AdditionalPaidInCapitalMember" xlink:type="locator" xlink:label="us-gaap_AdditionalPaidInCapitalMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CommonStockMember" xlink:type="locator" xlink:label="us-gaap_CommonStockMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PreferredStockMember" xlink:type="locator" xlink:label="us-gaap_PreferredStockMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_EquityComponentDomain" xlink:type="locator" xlink:label="us-gaap_EquityComponentDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:type="locator" xlink:label="us-gaap_StatementEquityComponentsAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StatementTable" xlink:type="locator" xlink:label="us-gaap_StatementTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StatementOfStockholdersEquityAbstract" xlink:type="locator" xlink:label="us-gaap_StatementOfStockholdersEquityAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfStockholdersEquityAbstract" xlink:to="us-gaap_StatementTable" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementEquityComponentsAxis" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementEquityComponentsAxis" xlink:to="us-gaap_EquityComponentDomain" order="10050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_PreferredStockMember" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_CommonStockMember" order="10110.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_AdditionalPaidInCapitalMember" order="10150.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_AccumulatedOtherComprehensiveIncomeMember" order="10170.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_AccumulatedDeficitDuringDevelopmentStageMember" order="10190.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_NoncontrollingInterestMember" order="10210.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementClassOfStockAxis" order="10030.02" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" order="10240.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtFiveDollarAndEightySixCentsPerShareMember" order="10260.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtEighteenDollarAndNinetyFiveCentsPerShareMember" order="10300.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_PreferredStockIssuedAtThousandDollarPerShareMember" order="10340.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedToGallowayMember" order="10380.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedToNovartisAtSevenDollarAndFiftyThreeCentsPerShareMember" order="10420.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementLineItems" order="10660.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" order="10670.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_SharesIssued" order="10990.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="arwr_StockIssuedDuringPeriodValueExerciseOfWarrants" order="11230.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="arwr_StockIssuedDuringPeriodSharesExerciseOfWarrants" order="11490.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised" order="11710.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" order="11970.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" order="12190.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="arwr_ExchangeRightsExercisedDuringPeriodValue" order="12430.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="arwr_ExchangeRightsExercisedDuringPeriodShares" order="12630.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodValueNewIssues" order="12830.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodSharesNewIssues" order="13090.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax" order="14750.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodValueConversionOfUnits" order="14990.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodSharesConversionOfUnits" order="15250.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_NoncontrollingInterestDecreaseFromDeconsolidation" order="15490.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross" order="15730.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross" order="15930.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_OtherComprehensiveIncomeLossNetOfTax" order="16530.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ProfitLoss" order="16730.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_li0l2" order="16990.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_SharesIssued_li0l2" order="17290.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax" order="22650.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/StatementConsolidatedStatementOfStockholdersEquityUnauditedParenthetical" xlink:href="arwr-20150331.xsd#Role_StatementConsolidatedStatementOfStockholdersEquityUnauditedParenthetical" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/StatementConsolidatedStatementOfStockholdersEquityUnauditedParenthetical">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SharesIssuedPricePerShare" xlink:type="locator" xlink:label="us-gaap_SharesIssuedPricePerShare" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StatementLineItems" xlink:type="locator" xlink:label="us-gaap_StatementLineItems" />
    <loc xlink:href="arwr-20150331.xsd#arwr_IssuedToNovartisAtSevenDollarAndFiftyThreeCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedToNovartisAtSevenDollarAndFiftyThreeCentsPerShareMember" />
    <loc xlink:href="arwr-20150331.xsd#arwr_PreferredStockIssuedAtThousandDollarPerShareMember" xlink:type="locator" xlink:label="arwr_PreferredStockIssuedAtThousandDollarPerShareMember" />
    <loc xlink:href="arwr-20150331.xsd#arwr_IssuedAtEighteenDollarAndNinetyFiveCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtEighteenDollarAndNinetyFiveCentsPerShareMember" />
    <loc xlink:href="arwr-20150331.xsd#arwr_IssuedAtFiveDollarAndEightySixCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtFiveDollarAndEightySixCentsPerShareMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:type="locator" xlink:label="us-gaap_ClassOfStockDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:type="locator" xlink:label="us-gaap_StatementClassOfStockAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StatementTable" xlink:type="locator" xlink:label="us-gaap_StatementTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StatementOfStockholdersEquityAbstract" xlink:type="locator" xlink:label="us-gaap_StatementOfStockholdersEquityAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfStockholdersEquityAbstract" xlink:to="us-gaap_StatementTable" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementClassOfStockAxis" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" order="10050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtFiveDollarAndEightySixCentsPerShareMember" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtEighteenDollarAndNinetyFiveCentsPerShareMember" order="10090.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_PreferredStockIssuedAtThousandDollarPerShareMember" order="10110.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedToNovartisAtSevenDollarAndFiftyThreeCentsPerShareMember" order="10130.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementLineItems" order="10150.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_SharesIssuedPricePerShare" order="10160.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/StatementConsolidatedStatementsOfCashFlowsUnaudited" xlink:href="arwr-20150331.xsd#Role_StatementConsolidatedStatementsOfCashFlowsUnaudited" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/StatementConsolidatedStatementsOfCashFlowsUnaudited">
    <loc xlink:href="arwr-20150331.xsd#arwr_CommonStockIssuedForAssetAcquisition" xlink:type="locator" xlink:label="arwr_CommonStockIssuedForAssetAcquisition" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_InterestPaid" xlink:type="locator" xlink:label="us-gaap_InterestPaid" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SupplementalCashFlowInformationAbstract" xlink:type="locator" xlink:label="us-gaap_SupplementalCashFlowInformationAbstract" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:type="locator" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_li0l2" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:type="locator" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease" xlink:type="locator" xlink:label="us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" xlink:type="locator" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" />
    <loc xlink:href="arwr-20150331.xsd#arwr_ProceedsFromExerciseOfWarrantsAndStockOptions" xlink:type="locator" xlink:label="arwr_ProceedsFromExerciseOfWarrantsAndStockOptions" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ProceedsFromIssuanceOrSaleOfEquity" xlink:type="locator" xlink:label="us-gaap_ProceedsFromIssuanceOrSaleOfEquity" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RepaymentsOfLongTermCapitalLeaseObligations" xlink:type="locator" xlink:label="us-gaap_RepaymentsOfLongTermCapitalLeaseObligations" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract" xlink:type="locator" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperations" xlink:type="locator" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperations" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities" xlink:type="locator" xlink:label="us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PaymentsToAcquireMarketableSecurities" xlink:type="locator" xlink:label="us-gaap_PaymentsToAcquireMarketableSecurities" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment" xlink:type="locator" xlink:label="us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:type="locator" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PaymentsToAcquireAssetsInvestingActivities" xlink:type="locator" xlink:label="us-gaap_PaymentsToAcquireAssetsInvestingActivities" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract" xlink:type="locator" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations" xlink:type="locator" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IncreaseDecreaseInOtherOperatingLiabilities" xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingLiabilities" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IncreaseDecreaseInAccruedLiabilities" xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInAccruedLiabilities" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsPayable" xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IncreaseDecreaseInOtherCurrentAssets" xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInOtherCurrentAssets" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IncreaseDecreaseInOtherReceivables" xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInOtherReceivables" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IncreaseDecreaseInReceivables" xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInReceivables" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest" xlink:type="locator" xlink:label="us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_li0l2" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AmortizationOfDebtDiscountPremium" xlink:type="locator" xlink:label="us-gaap_AmortizationOfDebtDiscountPremium" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DepreciationAndAmortization" xlink:type="locator" xlink:label="us-gaap_DepreciationAndAmortization" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensation" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensation" />
    <loc xlink:href="arwr-20150331.xsd#arwr_AcquiredInProcessResearchAndDevelopment" xlink:type="locator" xlink:label="arwr_AcquiredInProcessResearchAndDevelopment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_UnrealizedGainLossOnDerivatives" xlink:type="locator" xlink:label="us-gaap_UnrealizedGainLossOnDerivatives" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_GainLossOnSaleOfPropertyPlantEquipment" xlink:type="locator" xlink:label="us-gaap_GainLossOnSaleOfPropertyPlantEquipment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NetIncomeLoss" xlink:type="locator" xlink:label="us-gaap_NetIncomeLoss" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest" xlink:type="locator" xlink:label="us-gaap_NetIncomeLossAttributableToNoncontrollingInterest" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ProfitLoss" xlink:type="locator" xlink:label="us-gaap_ProfitLoss" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:type="locator" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StatementOfCashFlowsAbstract" xlink:type="locator" xlink:label="us-gaap_StatementOfCashFlowsAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" order="10260.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_ProfitLoss" order="10340.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_NetIncomeLossAttributableToNoncontrollingInterest" order="10380.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_NetIncomeLoss" order="10420.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_GainLossOnSaleOfPropertyPlantEquipment" order="10460.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_UnrealizedGainLossOnDerivatives" order="10500.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:to="arwr_AcquiredInProcessResearchAndDevelopment" order="10540.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_ShareBasedCompensation" order="10580.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_DepreciationAndAmortization" order="10620.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_AmortizationOfDebtDiscountPremium" order="10660.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_li0l2" order="10740.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" order="10780.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="us-gaap_IncreaseDecreaseInReceivables" order="10860.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="us-gaap_IncreaseDecreaseInOtherReceivables" order="10920.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="us-gaap_IncreaseDecreaseInOtherCurrentAssets" order="11000.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="us-gaap_IncreaseDecreaseInAccountsPayable" order="11080.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="us-gaap_IncreaseDecreaseInAccruedLiabilities" order="11160.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="us-gaap_IncreaseDecreaseInOtherOperatingLiabilities" order="11240.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations" order="11320.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract" order="11400.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_PaymentsToAcquireAssetsInvestingActivities" order="11480.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" order="11540.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment" order="11620.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_PaymentsToAcquireMarketableSecurities" order="11680.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities" order="11740.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperations" order="11820.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract" order="11900.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_RepaymentsOfLongTermCapitalLeaseObligations" order="11980.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_ProceedsFromIssuanceOrSaleOfEquity" order="12060.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract" xlink:to="arwr_ProceedsFromExerciseOfWarrantsAndStockOptions" order="12120.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" order="12200.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease" order="12280.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue" order="12360.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue_li0l2" order="12420.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_SupplementalCashFlowInformationAbstract" order="12480.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SupplementalCashFlowInformationAbstract" xlink:to="us-gaap_InterestPaid" order="12560.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SupplementalCashFlowInformationAbstract" xlink:to="arwr_CommonStockIssuedForAssetAcquisition" order="12640.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureOrganizationAndSignificantAccountingPolicies" xlink:href="arwr-20150331.xsd#Role_DisclosureOrganizationAndSignificantAccountingPolicies" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureOrganizationAndSignificantAccountingPolicies">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureAndSignificantAccountingPoliciesTextBlock" xlink:type="locator" xlink:label="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureAndSignificantAccountingPoliciesTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AccountingPoliciesAbstract" xlink:type="locator" xlink:label="us-gaap_AccountingPoliciesAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureAndSignificantAccountingPoliciesTextBlock" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureAcquisitions" xlink:href="arwr-20150331.xsd#Role_DisclosureAcquisitions" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureAcquisitions">
    <loc xlink:href="arwr-20150331.xsd#arwr_AssetAcquisitionDisclosureTextBlock" xlink:type="locator" xlink:label="arwr_AssetAcquisitionDisclosureTextBlock" />
    <loc xlink:href="arwr-20150331.xsd#arwr_AssetAcquisitionAbstract" xlink:type="locator" xlink:label="arwr_AssetAcquisitionAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_AssetAcquisitionAbstract" xlink:to="arwr_AssetAcquisitionDisclosureTextBlock" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosurePropertyAndEquipment" xlink:href="arwr-20150331.xsd#Role_DisclosurePropertyAndEquipment" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosurePropertyAndEquipment">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock" xlink:type="locator" xlink:label="us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PropertyPlantAndEquipmentAbstract" xlink:type="locator" xlink:label="us-gaap_PropertyPlantAndEquipmentAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentAbstract" xlink:to="us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureInvestments" xlink:href="arwr-20150331.xsd#Role_DisclosureInvestments" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureInvestments">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CostAndEquityMethodInvestmentsDisclosureTextBlock" xlink:type="locator" xlink:label="us-gaap_CostAndEquityMethodInvestmentsDisclosureTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_InvestmentsAllOtherInvestmentsAbstract" xlink:type="locator" xlink:label="us-gaap_InvestmentsAllOtherInvestmentsAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_InvestmentsAllOtherInvestmentsAbstract" xlink:to="us-gaap_CostAndEquityMethodInvestmentsDisclosureTextBlock" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureIntangibleAssets" xlink:href="arwr-20150331.xsd#Role_DisclosureIntangibleAssets" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureIntangibleAssets">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IntangibleAssetsDisclosureTextBlock" xlink:type="locator" xlink:label="us-gaap_IntangibleAssetsDisclosureTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" xlink:type="locator" xlink:label="us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" xlink:to="us-gaap_IntangibleAssetsDisclosureTextBlock" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureStockholdersEquity" xlink:href="arwr-20150331.xsd#Role_DisclosureStockholdersEquity" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureStockholdersEquity">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockholdersEquityNoteDisclosureTextBlock" xlink:type="locator" xlink:label="us-gaap_StockholdersEquityNoteDisclosureTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_EquityAbstract" xlink:type="locator" xlink:label="us-gaap_EquityAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EquityAbstract" xlink:to="us-gaap_StockholdersEquityNoteDisclosureTextBlock" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureCommitmentsAndContingencies" xlink:href="arwr-20150331.xsd#Role_DisclosureCommitmentsAndContingencies" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureCommitmentsAndContingencies">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:type="locator" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:type="locator" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:to="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureStockBasedCompensation" xlink:href="arwr-20150331.xsd#Role_DisclosureStockBasedCompensation" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureStockBasedCompensation">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xlink:type="locator" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:type="locator" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureFairValueMeasurements" xlink:href="arwr-20150331.xsd#Role_DisclosureFairValueMeasurements" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureFairValueMeasurements">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueDisclosuresTextBlock" xlink:type="locator" xlink:label="us-gaap_FairValueDisclosuresTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueDisclosuresAbstract" xlink:type="locator" xlink:label="us-gaap_FairValueDisclosuresAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="us-gaap_FairValueDisclosuresTextBlock" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureOrganizationAndSignificantAccountingPoliciesPolicies" xlink:href="arwr-20150331.xsd#Role_DisclosureOrganizationAndSignificantAccountingPoliciesPolicies" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureOrganizationAndSignificantAccountingPoliciesPolicies">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IncomeTaxPolicyTextBlock" xlink:type="locator" xlink:label="us-gaap_IncomeTaxPolicyTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DerivativesPolicyTextBlock" xlink:type="locator" xlink:label="us-gaap_DerivativesPolicyTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_EarningsPerSharePolicyTextBlock" xlink:type="locator" xlink:label="us-gaap_EarningsPerSharePolicyTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ResearchAndDevelopmentExpensePolicy" xlink:type="locator" xlink:label="us-gaap_ResearchAndDevelopmentExpensePolicy" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_TradeAndOtherAccountsReceivablePolicy" xlink:type="locator" xlink:label="us-gaap_TradeAndOtherAccountsReceivablePolicy" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RevenueRecognitionPolicyTextBlock" xlink:type="locator" xlink:label="us-gaap_RevenueRecognitionPolicyTextBlock" />
    <loc xlink:href="arwr-20150331.xsd#arwr_ContingentConsiderationPolicyTextBlock" xlink:type="locator" xlink:label="arwr_ContingentConsiderationPolicyTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_InProcessResearchAndDevelopmentPolicy" xlink:type="locator" xlink:label="us-gaap_InProcessResearchAndDevelopmentPolicy" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_GoodwillAndIntangibleAssetsPolicyTextBlock" xlink:type="locator" xlink:label="us-gaap_GoodwillAndIntangibleAssetsPolicyTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" xlink:type="locator" xlink:label="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_InvestmentPolicyTextBlock" xlink:type="locator" xlink:label="us-gaap_InvestmentPolicyTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ConcentrationRiskCreditRisk" xlink:type="locator" xlink:label="us-gaap_ConcentrationRiskCreditRisk" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy" xlink:type="locator" xlink:label="us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy" />
    <loc xlink:href="arwr-20150331.xsd#arwr_BasisOfPresentationAndUseOfEstimatesPolicyTextBlock" xlink:type="locator" xlink:label="arwr_BasisOfPresentationAndUseOfEstimatesPolicyTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ConsolidationPolicyTextBlock" xlink:type="locator" xlink:label="us-gaap_ConsolidationPolicyTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LiquidityDisclosureTextBlock" xlink:type="locator" xlink:label="us-gaap_LiquidityDisclosureTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessDescriptionAndAccountingPoliciesTextBlock" xlink:type="locator" xlink:label="us-gaap_BusinessDescriptionAndAccountingPoliciesTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AccountingPoliciesAbstract" xlink:type="locator" xlink:label="us-gaap_AccountingPoliciesAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_BusinessDescriptionAndAccountingPoliciesTextBlock" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_LiquidityDisclosureTextBlock" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_ConsolidationPolicyTextBlock" order="10050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="arwr_BasisOfPresentationAndUseOfEstimatesPolicyTextBlock" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy" order="10090.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_ConcentrationRiskCreditRisk" order="10110.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_InvestmentPolicyTextBlock" order="10130.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" order="10150.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_GoodwillAndIntangibleAssetsPolicyTextBlock" order="10170.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_InProcessResearchAndDevelopmentPolicy" order="10190.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="arwr_ContingentConsiderationPolicyTextBlock" order="10210.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_RevenueRecognitionPolicyTextBlock" order="10230.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_TradeAndOtherAccountsReceivablePolicy" order="10250.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_ResearchAndDevelopmentExpensePolicy" order="10270.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_EarningsPerSharePolicyTextBlock" order="10290.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy" order="10310.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_DerivativesPolicyTextBlock" order="10330.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_IncomeTaxPolicyTextBlock" order="10350.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureAcquisitionsTables" xlink:href="arwr-20150331.xsd#Role_DisclosureAcquisitionsTables" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureAcquisitionsTables">
    <loc xlink:href="arwr-20150331.xsd#arwr_SummaryOfPurchaseConsiderationTableTextBlock" xlink:type="locator" xlink:label="arwr_SummaryOfPurchaseConsiderationTableTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock" xlink:type="locator" xlink:label="us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock" />
    <loc xlink:href="arwr-20150331.xsd#arwr_AssetAcquisitionAbstract" xlink:type="locator" xlink:label="arwr_AssetAcquisitionAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_AssetAcquisitionAbstract" xlink:to="us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_AssetAcquisitionAbstract" xlink:to="arwr_SummaryOfPurchaseConsiderationTableTextBlock" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosurePropertyAndEquipmentTables" xlink:href="arwr-20150331.xsd#Role_DisclosurePropertyAndEquipmentTables" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosurePropertyAndEquipmentTables">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTextBlock" xlink:type="locator" xlink:label="us-gaap_PropertyPlantAndEquipmentTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PropertyPlantAndEquipmentAbstract" xlink:type="locator" xlink:label="us-gaap_PropertyPlantAndEquipmentAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentAbstract" xlink:to="us-gaap_PropertyPlantAndEquipmentTextBlock" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureInvestmentsTables" xlink:href="arwr-20150331.xsd#Role_DisclosureInvestmentsTables" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureInvestmentsTables">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_HeldToMaturitySecuritiesTextBlock" xlink:type="locator" xlink:label="us-gaap_HeldToMaturitySecuritiesTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_EquityAbstract" xlink:type="locator" xlink:label="us-gaap_EquityAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EquityAbstract" xlink:to="us-gaap_HeldToMaturitySecuritiesTextBlock" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureIntangibleAssetsTables" xlink:href="arwr-20150331.xsd#Role_DisclosureIntangibleAssetsTables" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureIntangibleAssetsTables">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfIntangibleAssetsAndGoodwillTableTextBlock" xlink:type="locator" xlink:label="us-gaap_ScheduleOfIntangibleAssetsAndGoodwillTableTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" xlink:type="locator" xlink:label="us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" xlink:to="us-gaap_ScheduleOfIntangibleAssetsAndGoodwillTableTextBlock" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureStockholdersEquityTables" xlink:href="arwr-20150331.xsd#Role_DisclosureStockholdersEquityTables" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureStockholdersEquityTables">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfStockholdersEquityNoteWarrantsOrRightsTextBlock" xlink:type="locator" xlink:label="us-gaap_ScheduleOfStockholdersEquityNoteWarrantsOrRightsTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_EquityAbstract" xlink:type="locator" xlink:label="us-gaap_EquityAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EquityAbstract" xlink:to="us-gaap_ScheduleOfStockholdersEquityNoteWarrantsOrRightsTextBlock" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureCommitmentsAndContingenciesTables" xlink:href="arwr-20150331.xsd#Role_DisclosureCommitmentsAndContingenciesTables" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureCommitmentsAndContingenciesTables">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesTableTextBlock" xlink:type="locator" xlink:label="us-gaap_ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesTableTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfFutureMinimumLeasePaymentsForCapitalLeasesTableTextBlock" xlink:type="locator" xlink:label="us-gaap_ScheduleOfFutureMinimumLeasePaymentsForCapitalLeasesTableTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LeasesAbstract" xlink:type="locator" xlink:label="us-gaap_LeasesAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeasesAbstract" xlink:to="us-gaap_ScheduleOfFutureMinimumLeasePaymentsForCapitalLeasesTableTextBlock" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeasesAbstract" xlink:to="us-gaap_ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesTableTextBlock" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureStockBasedCompensationTables" xlink:href="arwr-20150331.xsd#Role_DisclosureStockBasedCompensationTables" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureStockBasedCompensationTables">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationRestrictedStockUnitsAwardActivityTableTextBlock" xlink:type="locator" xlink:label="us-gaap_ScheduleOfShareBasedCompensationRestrictedStockUnitsAwardActivityTableTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock" xlink:type="locator" xlink:label="us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock" xlink:type="locator" xlink:label="us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:type="locator" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_ScheduleOfShareBasedCompensationRestrictedStockUnitsAwardActivityTableTextBlock" order="10050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureFairValueMeasurementsTables" xlink:href="arwr-20150331.xsd#Role_DisclosureFairValueMeasurementsTables" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureFairValueMeasurementsTables">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionContingentConsiderationTextBlock" xlink:type="locator" xlink:label="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionContingentConsiderationTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlock" xlink:type="locator" xlink:label="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock" xlink:type="locator" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock" xlink:type="locator" xlink:label="us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" xlink:type="locator" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" />
    <loc xlink:href="arwr-20150331.xsd#arwr_ExchangeRightsMember" xlink:type="locator" xlink:label="arwr_ExchangeRightsMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:type="locator" xlink:label="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueByLiabilityClassAxis" xlink:type="locator" xlink:label="us-gaap_FairValueByLiabilityClassAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_WarrantMember" xlink:type="locator" xlink:label="us-gaap_WarrantMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:type="locator" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FinancialInstrumentAxis" xlink:type="locator" xlink:label="us-gaap_FinancialInstrumentAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" xlink:type="locator" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueDisclosuresAbstract" xlink:type="locator" xlink:label="us-gaap_FairValueDisclosuresAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" xlink:to="us-gaap_FinancialInstrumentAxis" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancialInstrumentAxis" xlink:to="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" order="10050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="us-gaap_WarrantMember" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" xlink:to="us-gaap_FairValueByLiabilityClassAxis" order="10030.02" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueByLiabilityClassAxis" xlink:to="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" order="10150.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:to="arwr_ExchangeRightsMember" order="10170.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" order="10240.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" xlink:to="us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock" order="10250.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock" order="10300.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" xlink:to="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlock" order="10350.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" xlink:to="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionContingentConsiderationTextBlock" order="10500.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureOrganizationAndSignificantAccountingPoliciesAdditionalInformationDetail" xlink:href="arwr-20150331.xsd#Role_DisclosureOrganizationAndSignificantAccountingPoliciesAdditionalInformationDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureOrganizationAndSignificantAccountingPoliciesAdditionalInformationDetail">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:type="locator" xlink:label="us-gaap_PropertyPlantAndEquipmentUsefulLife" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CashFDICInsuredAmount" xlink:type="locator" xlink:label="us-gaap_CashFDICInsuredAmount" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RestrictedCashAndCashEquivalents" xlink:type="locator" xlink:label="us-gaap_RestrictedCashAndCashEquivalents" />
    <loc xlink:href="arwr-20150331.xsd#arwr_ProceedsFromExerciseOfWarrantsAndStockOptions" xlink:type="locator" xlink:label="arwr_ProceedsFromExerciseOfWarrantsAndStockOptions" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities" xlink:type="locator" xlink:label="us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:type="locator" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PaymentsToAcquireAssetsInvestingActivities" xlink:type="locator" xlink:label="us-gaap_PaymentsToAcquireAssetsInvestingActivities" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations" xlink:type="locator" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease" xlink:type="locator" xlink:label="us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_HeldToMaturitySecurities" xlink:type="locator" xlink:label="us-gaap_HeldToMaturitySecurities" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DebtInstrumentMaturityDateDescription" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentMaturityDateDescription" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:type="locator" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfInvestmentsLineItems" xlink:type="locator" xlink:label="us-gaap_ScheduleOfInvestmentsLineItems" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_MaximumMember" xlink:type="locator" xlink:label="us-gaap_MaximumMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_MinimumMember" xlink:type="locator" xlink:label="us-gaap_MinimumMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RangeMember" xlink:type="locator" xlink:label="us-gaap_RangeMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RangeAxis" xlink:type="locator" xlink:label="us-gaap_RangeAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BondsMember" xlink:type="locator" xlink:label="us-gaap_BondsMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SummaryOfInvestmentsByTypeDomain" xlink:type="locator" xlink:label="us-gaap_SummaryOfInvestmentsByTypeDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SummaryOfInvestmentsOtherThanInvestmentsInRelatedPartiesByTypeAxis" xlink:type="locator" xlink:label="us-gaap_SummaryOfInvestmentsOtherThanInvestmentsInRelatedPartiesByTypeAxis" />
    <loc xlink:href="arwr-20150331.xsd#arwr_NovartisMember" xlink:type="locator" xlink:label="arwr_NovartisMember" />
    <loc xlink:href="arwr-20150331.xsd#arwr_AssetAcquisitionDomain" xlink:type="locator" xlink:label="arwr_AssetAcquisitionDomain" />
    <loc xlink:href="arwr-20150331.xsd#arwr_AssetAcquisitionAxis" xlink:type="locator" xlink:label="arwr_AssetAcquisitionAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfInvestmentsTable" xlink:type="locator" xlink:label="us-gaap_ScheduleOfInvestmentsTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AccountingPoliciesAbstract" xlink:type="locator" xlink:label="us-gaap_AccountingPoliciesAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_ScheduleOfInvestmentsTable" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsTable" xlink:to="arwr_AssetAcquisitionAxis" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_AssetAcquisitionAxis" xlink:to="arwr_AssetAcquisitionDomain" order="10050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_AssetAcquisitionDomain" xlink:to="arwr_NovartisMember" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsTable" xlink:to="us-gaap_SummaryOfInvestmentsOtherThanInvestmentsInRelatedPartiesByTypeAxis" order="10030.02" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SummaryOfInvestmentsOtherThanInvestmentsInRelatedPartiesByTypeAxis" xlink:to="us-gaap_SummaryOfInvestmentsByTypeDomain" order="10100.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SummaryOfInvestmentsByTypeDomain" xlink:to="us-gaap_BondsMember" order="10120.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsTable" xlink:to="us-gaap_RangeAxis" order="10030.04" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RangeAxis" xlink:to="us-gaap_RangeMember" order="10170.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RangeMember" xlink:to="us-gaap_MinimumMember" order="10190.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RangeMember" xlink:to="us-gaap_MaximumMember" order="10210.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsTable" xlink:to="us-gaap_ScheduleOfInvestmentsLineItems" order="10230.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue" order="10240.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="us-gaap_DebtInstrumentMaturityDateDescription" order="10280.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="us-gaap_HeldToMaturitySecurities" order="10340.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease" order="10400.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations" order="10440.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="us-gaap_PaymentsToAcquireAssetsInvestingActivities" order="10480.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" order="10540.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities" order="10580.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="arwr_ProceedsFromExerciseOfWarrantsAndStockOptions" order="10620.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="us-gaap_RestrictedCashAndCashEquivalents" order="10690.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="us-gaap_CashFDICInsuredAmount" order="10800.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="us-gaap_PropertyPlantAndEquipmentUsefulLife" order="10870.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureAcquisitionsAdditionalInformationDetail" xlink:href="arwr-20150331.xsd#Role_DisclosureAcquisitionsAdditionalInformationDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureAcquisitionsAdditionalInformationDetail">
    <loc xlink:href="arwr-20150331.xsd#arwr_ObligationToPayRoyalties" xlink:type="locator" xlink:label="arwr_ObligationToPayRoyalties" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesAcquisitions" xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodSharesAcquisitions" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PaymentsToAcquireAssetsInvestingActivities" xlink:type="locator" xlink:label="us-gaap_PaymentsToAcquireAssetsInvestingActivities" />
    <loc xlink:href="arwr-20150331.xsd#arwr_AssetAcquisitionLineItems" xlink:type="locator" xlink:label="arwr_AssetAcquisitionLineItems" />
    <loc xlink:href="arwr-20150331.xsd#arwr_NovartisMember" xlink:type="locator" xlink:label="arwr_NovartisMember" />
    <loc xlink:href="arwr-20150331.xsd#arwr_AssetAcquisitionDomain" xlink:type="locator" xlink:label="arwr_AssetAcquisitionDomain" />
    <loc xlink:href="arwr-20150331.xsd#arwr_AssetAcquisitionAxis" xlink:type="locator" xlink:label="arwr_AssetAcquisitionAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SubsequentEventMember" xlink:type="locator" xlink:label="us-gaap_SubsequentEventMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:type="locator" xlink:label="us-gaap_SubsequentEventTypeDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SubsequentEventTypeAxis" xlink:type="locator" xlink:label="us-gaap_SubsequentEventTypeAxis" />
    <loc xlink:href="arwr-20150331.xsd#arwr_AssetAcquisitionTable" xlink:type="locator" xlink:label="arwr_AssetAcquisitionTable" />
    <loc xlink:href="arwr-20150331.xsd#arwr_AssetAcquisitionAbstract" xlink:type="locator" xlink:label="arwr_AssetAcquisitionAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_AssetAcquisitionAbstract" xlink:to="arwr_AssetAcquisitionTable" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_AssetAcquisitionTable" xlink:to="us-gaap_SubsequentEventTypeAxis" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SubsequentEventTypeAxis" xlink:to="us-gaap_SubsequentEventTypeDomain" order="10050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SubsequentEventTypeDomain" xlink:to="us-gaap_SubsequentEventMember" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_AssetAcquisitionTable" xlink:to="arwr_AssetAcquisitionAxis" order="10030.02" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_AssetAcquisitionAxis" xlink:to="arwr_AssetAcquisitionDomain" order="10100.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_AssetAcquisitionDomain" xlink:to="arwr_NovartisMember" order="10120.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_AssetAcquisitionTable" xlink:to="arwr_AssetAcquisitionLineItems" order="10250.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_AssetAcquisitionLineItems" xlink:to="us-gaap_PaymentsToAcquireAssetsInvestingActivities" order="10260.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_AssetAcquisitionLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodSharesAcquisitions" order="10480.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_AssetAcquisitionLineItems" xlink:to="arwr_ObligationToPayRoyalties" order="10590.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureAcquisitionsSummaryOfEstimatedFairValuesAtDateOfAcquisitionDetail" xlink:href="arwr-20150331.xsd#Role_DisclosureAcquisitionsSummaryOfEstimatedFairValuesAtDateOfAcquisitionDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureAcquisitionsSummaryOfEstimatedFairValuesAtDateOfAcquisitionDetail">
    <loc xlink:href="arwr-20150331.xsd#arwr_AcquiredInProcessResearchAndDevelopment" xlink:type="locator" xlink:label="arwr_AcquiredInProcessResearchAndDevelopment" />
    <loc xlink:href="arwr-20150331.xsd#arwr_AssetsAcquiredFiniteLivedIntangibleAssets" xlink:type="locator" xlink:label="arwr_AssetsAcquiredFiniteLivedIntangibleAssets" />
    <loc xlink:href="arwr-20150331.xsd#arwr_AssetAcquisitionLineItems" xlink:type="locator" xlink:label="arwr_AssetAcquisitionLineItems" />
    <loc xlink:href="arwr-20150331.xsd#arwr_LicenseMember" xlink:type="locator" xlink:label="arwr_LicenseMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PatentsMember" xlink:type="locator" xlink:label="us-gaap_PatentsMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:type="locator" xlink:label="us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:type="locator" xlink:label="us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" />
    <loc xlink:href="arwr-20150331.xsd#arwr_NovartisMember" xlink:type="locator" xlink:label="arwr_NovartisMember" />
    <loc xlink:href="arwr-20150331.xsd#arwr_AssetAcquisitionDomain" xlink:type="locator" xlink:label="arwr_AssetAcquisitionDomain" />
    <loc xlink:href="arwr-20150331.xsd#arwr_AssetAcquisitionAxis" xlink:type="locator" xlink:label="arwr_AssetAcquisitionAxis" />
    <loc xlink:href="arwr-20150331.xsd#arwr_AssetAcquisitionTable" xlink:type="locator" xlink:label="arwr_AssetAcquisitionTable" />
    <loc xlink:href="arwr-20150331.xsd#arwr_AssetAcquisitionAbstract" xlink:type="locator" xlink:label="arwr_AssetAcquisitionAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_AssetAcquisitionAbstract" xlink:to="arwr_AssetAcquisitionTable" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_AssetAcquisitionTable" xlink:to="arwr_AssetAcquisitionAxis" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_AssetAcquisitionAxis" xlink:to="arwr_AssetAcquisitionDomain" order="10050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_AssetAcquisitionDomain" xlink:to="arwr_NovartisMember" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_AssetAcquisitionTable" xlink:to="us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" order="10030.02" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:to="us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" order="10100.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="us-gaap_PatentsMember" order="10120.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="arwr_LicenseMember" order="10140.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_AssetAcquisitionTable" xlink:to="arwr_AssetAcquisitionLineItems" order="10160.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_AssetAcquisitionLineItems" xlink:to="arwr_AssetsAcquiredFiniteLivedIntangibleAssets" order="10170.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_AssetAcquisitionLineItems" xlink:to="arwr_AcquiredInProcessResearchAndDevelopment" order="10250.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureAcquisitionsSummaryOfPurchaseConsiderationDetail" xlink:href="arwr-20150331.xsd#Role_DisclosureAcquisitionsSummaryOfPurchaseConsiderationDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureAcquisitionsSummaryOfPurchaseConsiderationDetail">
    <loc xlink:href="arwr-20150331.xsd#arwr_AssetAcquisitionConsiderationTransferred" xlink:type="locator" xlink:label="arwr_AssetAcquisitionConsiderationTransferred" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueAcquisitions" xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodValueAcquisitions" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PaymentsToAcquireAssetsInvestingActivities" xlink:type="locator" xlink:label="us-gaap_PaymentsToAcquireAssetsInvestingActivities" />
    <loc xlink:href="arwr-20150331.xsd#arwr_AssetAcquisitionLineItems" xlink:type="locator" xlink:label="arwr_AssetAcquisitionLineItems" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SubsequentEventMember" xlink:type="locator" xlink:label="us-gaap_SubsequentEventMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:type="locator" xlink:label="us-gaap_SubsequentEventTypeDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SubsequentEventTypeAxis" xlink:type="locator" xlink:label="us-gaap_SubsequentEventTypeAxis" />
    <loc xlink:href="arwr-20150331.xsd#arwr_NovartisMember" xlink:type="locator" xlink:label="arwr_NovartisMember" />
    <loc xlink:href="arwr-20150331.xsd#arwr_AssetAcquisitionDomain" xlink:type="locator" xlink:label="arwr_AssetAcquisitionDomain" />
    <loc xlink:href="arwr-20150331.xsd#arwr_AssetAcquisitionAxis" xlink:type="locator" xlink:label="arwr_AssetAcquisitionAxis" />
    <loc xlink:href="arwr-20150331.xsd#arwr_AssetAcquisitionTable" xlink:type="locator" xlink:label="arwr_AssetAcquisitionTable" />
    <loc xlink:href="arwr-20150331.xsd#arwr_AssetAcquisitionAbstract" xlink:type="locator" xlink:label="arwr_AssetAcquisitionAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_AssetAcquisitionAbstract" xlink:to="arwr_AssetAcquisitionTable" order="10050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_AssetAcquisitionTable" xlink:to="arwr_AssetAcquisitionAxis" order="10060.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_AssetAcquisitionAxis" xlink:to="arwr_AssetAcquisitionDomain" order="10080.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_AssetAcquisitionDomain" xlink:to="arwr_NovartisMember" order="10100.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_AssetAcquisitionTable" xlink:to="us-gaap_SubsequentEventTypeAxis" order="10060.02" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SubsequentEventTypeAxis" xlink:to="us-gaap_SubsequentEventTypeDomain" order="10130.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SubsequentEventTypeDomain" xlink:to="us-gaap_SubsequentEventMember" order="10150.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_AssetAcquisitionTable" xlink:to="arwr_AssetAcquisitionLineItems" order="10170.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_AssetAcquisitionLineItems" xlink:to="us-gaap_PaymentsToAcquireAssetsInvestingActivities" order="10180.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_AssetAcquisitionLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodValueAcquisitions" order="10260.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_AssetAcquisitionLineItems" xlink:to="arwr_AssetAcquisitionConsiderationTransferred" order="10320.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosurePropertyAndEquipmentSummaryOfPropertyAndEquipmentDetail" xlink:href="arwr-20150331.xsd#Role_DisclosurePropertyAndEquipmentSummaryOfPropertyAndEquipmentDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosurePropertyAndEquipmentSummaryOfPropertyAndEquipmentDetail">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:type="locator" xlink:label="us-gaap_PropertyPlantAndEquipmentNet" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:type="locator" xlink:label="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PropertyPlantAndEquipmentGross" xlink:type="locator" xlink:label="us-gaap_PropertyPlantAndEquipmentGross" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LeaseholdImprovementsGross" xlink:type="locator" xlink:label="us-gaap_LeaseholdImprovementsGross" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CapitalizedComputerSoftwareGross" xlink:type="locator" xlink:label="us-gaap_CapitalizedComputerSoftwareGross" />
    <loc xlink:href="arwr-20150331.xsd#arwr_ResearchEquipment" xlink:type="locator" xlink:label="arwr_ResearchEquipment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FurnitureAndFixturesGross" xlink:type="locator" xlink:label="us-gaap_FurnitureAndFixturesGross" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PropertyPlantAndEquipmentAbstract" xlink:type="locator" xlink:label="us-gaap_PropertyPlantAndEquipmentAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentAbstract" xlink:to="us-gaap_FurnitureAndFixturesGross" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentAbstract" xlink:to="arwr_ResearchEquipment" order="10150.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentAbstract" xlink:to="us-gaap_CapitalizedComputerSoftwareGross" order="10230.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentAbstract" xlink:to="us-gaap_LeaseholdImprovementsGross" order="10310.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentAbstract" xlink:to="us-gaap_PropertyPlantAndEquipmentGross" order="10390.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentAbstract" xlink:to="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" order="10470.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentAbstract" xlink:to="us-gaap_PropertyPlantAndEquipmentNet" order="10550.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureInvestmentsSummaryOfShortAndLongTermInvestmentsDetail" xlink:href="arwr-20150331.xsd#Role_DisclosureInvestmentsSummaryOfShortAndLongTermInvestmentsDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureInvestmentsSummaryOfShortAndLongTermInvestmentsDetail">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_HeldToMaturitySecurities" xlink:type="locator" xlink:label="us-gaap_HeldToMaturitySecurities" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_HeldToMaturitySecuritiesNoncurrent" xlink:type="locator" xlink:label="us-gaap_HeldToMaturitySecuritiesNoncurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_HeldToMaturitySecuritiesCurrent" xlink:type="locator" xlink:label="us-gaap_HeldToMaturitySecuritiesCurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_HeldToMaturitySecuritiesFairValue" xlink:type="locator" xlink:label="us-gaap_HeldToMaturitySecuritiesFairValue" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss" xlink:type="locator" xlink:label="us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain" xlink:type="locator" xlink:label="us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfHeldToMaturitySecuritiesLineItems" xlink:type="locator" xlink:label="us-gaap_ScheduleOfHeldToMaturitySecuritiesLineItems" />
    <loc xlink:href="arwr-20150331.xsd#arwr_CommercialNotesDueAfterOneYearThroughTwoYearsMember" xlink:type="locator" xlink:label="arwr_CommercialNotesDueAfterOneYearThroughTwoYearsMember" />
    <loc xlink:href="arwr-20150331.xsd#arwr_CommercialNotesDueWithinOneYearMember" xlink:type="locator" xlink:label="arwr_CommercialNotesDueWithinOneYearMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain" xlink:type="locator" xlink:label="us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis" xlink:type="locator" xlink:label="us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfHeldToMaturitySecuritiesTable" xlink:type="locator" xlink:label="us-gaap_ScheduleOfHeldToMaturitySecuritiesTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_EquityAbstract" xlink:type="locator" xlink:label="us-gaap_EquityAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EquityAbstract" xlink:to="us-gaap_ScheduleOfHeldToMaturitySecuritiesTable" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfHeldToMaturitySecuritiesTable" xlink:to="us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis" xlink:to="us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain" order="10050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain" xlink:to="arwr_CommercialNotesDueWithinOneYearMember" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain" xlink:to="arwr_CommercialNotesDueAfterOneYearThroughTwoYearsMember" order="10090.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfHeldToMaturitySecuritiesTable" xlink:to="us-gaap_ScheduleOfHeldToMaturitySecuritiesLineItems" order="10180.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfHeldToMaturitySecuritiesLineItems" xlink:to="us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain" order="10190.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfHeldToMaturitySecuritiesLineItems" xlink:to="us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss" order="10330.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfHeldToMaturitySecuritiesLineItems" xlink:to="us-gaap_HeldToMaturitySecuritiesFairValue" order="10490.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfHeldToMaturitySecuritiesLineItems" xlink:to="us-gaap_HeldToMaturitySecuritiesCurrent" order="10700.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfHeldToMaturitySecuritiesLineItems" xlink:to="us-gaap_HeldToMaturitySecuritiesNoncurrent" order="10720.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfHeldToMaturitySecuritiesLineItems" xlink:to="us-gaap_HeldToMaturitySecurities" order="10740.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureIntangibleAssetsAdditionalInformationDetail" xlink:href="arwr-20150331.xsd#Role_DisclosureIntangibleAssetsAdditionalInformationDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureIntangibleAssetsAdditionalInformationDetail">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive" xlink:type="locator" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive" xlink:type="locator" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour" xlink:type="locator" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" xlink:type="locator" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" xlink:type="locator" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" xlink:type="locator" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRemainderOfFiscalYear" xlink:type="locator" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRemainderOfFiscalYear" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AmortizationOfIntangibleAssets" xlink:type="locator" xlink:label="us-gaap_AmortizationOfIntangibleAssets" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:type="locator" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:type="locator" xlink:label="us-gaap_FiniteLivedIntangibleAssetUsefulLife" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:type="locator" xlink:label="us-gaap_FiniteLivedIntangibleAssetsLineItems" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PatentsMember" xlink:type="locator" xlink:label="us-gaap_PatentsMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LicensingAgreementsMember" xlink:type="locator" xlink:label="us-gaap_LicensingAgreementsMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:type="locator" xlink:label="us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:type="locator" xlink:label="us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" />
    <loc xlink:href="arwr-20150331.xsd#arwr_RocheMadisonMember" xlink:type="locator" xlink:label="arwr_RocheMadisonMember" />
    <loc xlink:href="arwr-20150331.xsd#arwr_NovartisRNAiMember" xlink:type="locator" xlink:label="arwr_NovartisRNAiMember" />
    <loc xlink:href="arwr-20150331.xsd#arwr_AssetAcquisitionDomain" xlink:type="locator" xlink:label="arwr_AssetAcquisitionDomain" />
    <loc xlink:href="arwr-20150331.xsd#arwr_AssetAcquisitionAxis" xlink:type="locator" xlink:label="arwr_AssetAcquisitionAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" xlink:type="locator" xlink:label="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" xlink:type="locator" xlink:label="us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" xlink:to="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" xlink:to="arwr_AssetAcquisitionAxis" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_AssetAcquisitionAxis" xlink:to="arwr_AssetAcquisitionDomain" order="10050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_AssetAcquisitionDomain" xlink:to="arwr_NovartisRNAiMember" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_AssetAcquisitionDomain" xlink:to="arwr_RocheMadisonMember" order="10110.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" xlink:to="us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" order="10030.02" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:to="us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" order="10200.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="us-gaap_LicensingAgreementsMember" order="10220.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="us-gaap_PatentsMember" order="10300.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" xlink:to="us-gaap_FiniteLivedIntangibleAssetsLineItems" order="10340.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:to="us-gaap_FiniteLivedIntangibleAssetUsefulLife" order="10350.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" order="10450.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:to="us-gaap_AmortizationOfIntangibleAssets" order="10950.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRemainderOfFiscalYear" order="11190.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" order="11290.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" order="11390.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" order="11490.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour" order="11590.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive" order="11690.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive" order="11790.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureIntangibleAssetsScheduleOfIntangibleAssetsDetail" xlink:href="arwr-20150331.xsd#Role_DisclosureIntangibleAssetsScheduleOfIntangibleAssetsDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureIntangibleAssetsScheduleOfIntangibleAssetsDetail">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:type="locator" xlink:label="us-gaap_IntangibleAssetsNetExcludingGoodwill_li0l2" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill" xlink:type="locator" xlink:label="us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:type="locator" xlink:label="us-gaap_IntangibleAssetsNetExcludingGoodwill" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsNet" xlink:type="locator" xlink:label="us-gaap_FiniteLivedIntangibleAssetsNet_li0l2" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AmortizationOfIntangibleAssets" xlink:type="locator" xlink:label="us-gaap_AmortizationOfIntangibleAssets" />
    <loc xlink:href="arwr-20150331.xsd#arwr_AssetsAcquiredFiniteLivedIntangibleAssets" xlink:type="locator" xlink:label="arwr_AssetsAcquiredFiniteLivedIntangibleAssets" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ImpairmentOfIntangibleAssetsFinitelived" xlink:type="locator" xlink:label="us-gaap_ImpairmentOfIntangibleAssetsFinitelived" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsNet" xlink:type="locator" xlink:label="us-gaap_FiniteLivedIntangibleAssetsNet" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill" xlink:type="locator" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_li0l2" />
    <loc xlink:href="arwr-20150331.xsd#arwr_IndefiniteLivedIntangibleAssetsAmortization" xlink:type="locator" xlink:label="arwr_IndefiniteLivedIntangibleAssetsAmortization" />
    <loc xlink:href="arwr-20150331.xsd#arwr_AssetsAcquiredIndefiniteLivedIntangibleAssets" xlink:type="locator" xlink:label="arwr_AssetsAcquiredIndefiniteLivedIntangibleAssets" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill" xlink:type="locator" xlink:label="us-gaap_ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill" xlink:type="locator" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwillAbstract" xlink:type="locator" xlink:label="us-gaap_IntangibleAssetsNetExcludingGoodwillAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IntangibleAssetsNetExcludingGoodwillAbstract" xlink:to="us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IntangibleAssetsNetExcludingGoodwillAbstract" xlink:to="us-gaap_ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill" order="10110.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IntangibleAssetsNetExcludingGoodwillAbstract" xlink:to="arwr_AssetsAcquiredIndefiniteLivedIntangibleAssets" order="10210.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IntangibleAssetsNetExcludingGoodwillAbstract" xlink:to="arwr_IndefiniteLivedIntangibleAssetsAmortization" order="10290.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IntangibleAssetsNetExcludingGoodwillAbstract" xlink:to="us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_li0l2" order="10370.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IntangibleAssetsNetExcludingGoodwillAbstract" xlink:to="us-gaap_FiniteLivedIntangibleAssetsNet" order="10810.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IntangibleAssetsNetExcludingGoodwillAbstract" xlink:to="us-gaap_ImpairmentOfIntangibleAssetsFinitelived" order="10910.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IntangibleAssetsNetExcludingGoodwillAbstract" xlink:to="arwr_AssetsAcquiredFiniteLivedIntangibleAssets" order="10990.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IntangibleAssetsNetExcludingGoodwillAbstract" xlink:to="us-gaap_AmortizationOfIntangibleAssets" order="11070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IntangibleAssetsNetExcludingGoodwillAbstract" xlink:to="us-gaap_FiniteLivedIntangibleAssetsNet_li0l2" order="11170.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IntangibleAssetsNetExcludingGoodwillAbstract" xlink:to="us-gaap_IntangibleAssetsNetExcludingGoodwill" order="11630.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IntangibleAssetsNetExcludingGoodwillAbstract" xlink:to="us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill" order="11730.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IntangibleAssetsNetExcludingGoodwillAbstract" xlink:to="us-gaap_IntangibleAssetsNetExcludingGoodwill_li0l2" order="11990.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureStockholdersEquityAdditionalInformationDetail" xlink:href="arwr-20150331.xsd#Role_DisclosureStockholdersEquityAdditionalInformationDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureStockholdersEquityAdditionalInformationDetail">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:type="locator" xlink:label="us-gaap_ProceedsFromIssuanceOfCommonStock" />
    <loc xlink:href="arwr-20150331.xsd#arwr_AggregatePriceOnIssuanceOrSaleOfEquity" xlink:type="locator" xlink:label="arwr_AggregatePriceOnIssuanceOrSaleOfEquity" />
    <loc xlink:href="arwr-20150331.xsd#arwr_ConversionPricePerShare" xlink:type="locator" xlink:label="arwr_ConversionPricePerShare" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SaleOfStockPricePerShare" xlink:type="locator" xlink:label="us-gaap_SaleOfStockPricePerShare" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodSharesNewIssues" />
    <loc xlink:href="arwr-20150331.xsd#arwr_ThresholdPercentageOfCommonStockOwnershipUponPreferredStockConversion" xlink:type="locator" xlink:label="arwr_ThresholdPercentageOfCommonStockOwnershipUponPreferredStockConversion" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PreferredStockSharesOutstanding" xlink:type="locator" xlink:label="us-gaap_PreferredStockSharesOutstanding" />
    <loc xlink:href="arwr-20150331.xsd#arwr_CommonStockEquivalentOfPreferredStockSharesUponConversion" xlink:type="locator" xlink:label="arwr_CommonStockEquivalentOfPreferredStockSharesUponConversion" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CommonStockSharesOutstanding" xlink:type="locator" xlink:label="us-gaap_CommonStockSharesOutstanding" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PreferredStockParOrStatedValuePerShare" xlink:type="locator" xlink:label="us-gaap_PreferredStockParOrStatedValuePerShare" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PreferredStockSharesAuthorized" xlink:type="locator" xlink:label="us-gaap_PreferredStockSharesAuthorized" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CommonStockParOrStatedValuePerShare" xlink:type="locator" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CommonStockSharesAuthorized" xlink:type="locator" xlink:label="us-gaap_CommonStockSharesAuthorized" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CapitalUnitsAuthorized" xlink:type="locator" xlink:label="us-gaap_CapitalUnitsAuthorized" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ClassOfStockLineItems" xlink:type="locator" xlink:label="us-gaap_ClassOfStockLineItems" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SeriesCPreferredStockMember" xlink:type="locator" xlink:label="us-gaap_SeriesCPreferredStockMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:type="locator" xlink:label="us-gaap_ClassOfStockDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:type="locator" xlink:label="us-gaap_StatementClassOfStockAxis" />
    <loc xlink:href="arwr-20150331.xsd#arwr_TwoThousandFourEquityIncentivePlanTwoThousandThirteenEquityIncentivePlanAndInducementGrantsMember" xlink:type="locator" xlink:label="arwr_TwoThousandFourEquityIncentivePlanTwoThousandThirteenEquityIncentivePlanAndInducementGrantsMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PlanNameDomain" xlink:type="locator" xlink:label="us-gaap_PlanNameDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PlanNameAxis" xlink:type="locator" xlink:label="us-gaap_PlanNameAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfStockByClassTable" xlink:type="locator" xlink:label="us-gaap_ScheduleOfStockByClassTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_EquityAbstract" xlink:type="locator" xlink:label="us-gaap_EquityAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EquityAbstract" xlink:to="us-gaap_ScheduleOfStockByClassTable" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfStockByClassTable" xlink:to="us-gaap_PlanNameAxis" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PlanNameAxis" xlink:to="us-gaap_PlanNameDomain" order="10050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PlanNameDomain" xlink:to="arwr_TwoThousandFourEquityIncentivePlanTwoThousandThirteenEquityIncentivePlanAndInducementGrantsMember" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfStockByClassTable" xlink:to="us-gaap_StatementClassOfStockAxis" order="10030.02" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" order="10100.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_SeriesCPreferredStockMember" order="10120.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfStockByClassTable" xlink:to="us-gaap_ClassOfStockLineItems" order="10190.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_CapitalUnitsAuthorized" order="10200.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_CommonStockSharesAuthorized" order="10240.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_CommonStockParOrStatedValuePerShare" order="10260.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_PreferredStockSharesAuthorized" order="10280.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_PreferredStockParOrStatedValuePerShare" order="10300.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_CommonStockSharesOutstanding" order="10350.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="arwr_CommonStockEquivalentOfPreferredStockSharesUponConversion" order="10390.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_PreferredStockSharesOutstanding" order="10450.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" order="10510.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="arwr_ThresholdPercentageOfCommonStockOwnershipUponPreferredStockConversion" order="10600.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodSharesNewIssues" order="10670.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_SaleOfStockPricePerShare" order="10750.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="arwr_ConversionPricePerShare" order="10830.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="arwr_AggregatePriceOnIssuanceOrSaleOfEquity" order="10890.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_ProceedsFromIssuanceOfCommonStock" order="10950.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureStockholdersEquitySummaryOfInformationAboutWarrantsDetail" xlink:href="arwr-20150331.xsd#Role_DisclosureStockholdersEquitySummaryOfInformationAboutWarrantsDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureStockholdersEquitySummaryOfInformationAboutWarrantsDetail">
    <loc xlink:href="arwr-20150331.xsd#arwr_RemainingLifeOfWarrant" xlink:type="locator" xlink:label="arwr_RemainingLifeOfWarrant" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ClassOfWarrantOrRightOutstanding" xlink:type="locator" xlink:label="us-gaap_ClassOfWarrantOrRightOutstanding" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" xlink:type="locator" xlink:label="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ClassOfWarrantOrRightLineItems" xlink:type="locator" xlink:label="us-gaap_ClassOfWarrantOrRightLineItems" />
    <loc xlink:href="arwr-20150331.xsd#arwr_WarrantEightMember" xlink:type="locator" xlink:label="arwr_WarrantEightMember" />
    <loc xlink:href="arwr-20150331.xsd#arwr_WarrantSevenMember" xlink:type="locator" xlink:label="arwr_WarrantSevenMember" />
    <loc xlink:href="arwr-20150331.xsd#arwr_WarrantSixMember" xlink:type="locator" xlink:label="arwr_WarrantSixMember" />
    <loc xlink:href="arwr-20150331.xsd#arwr_WarrantFiveMember" xlink:type="locator" xlink:label="arwr_WarrantFiveMember" />
    <loc xlink:href="arwr-20150331.xsd#arwr_WarrantFourMember" xlink:type="locator" xlink:label="arwr_WarrantFourMember" />
    <loc xlink:href="arwr-20150331.xsd#arwr_WarrantThreeMember" xlink:type="locator" xlink:label="arwr_WarrantThreeMember" />
    <loc xlink:href="arwr-20150331.xsd#arwr_WarrantTwoMember" xlink:type="locator" xlink:label="arwr_WarrantTwoMember" />
    <loc xlink:href="arwr-20150331.xsd#arwr_WarrantOneMember" xlink:type="locator" xlink:label="arwr_WarrantOneMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ClassOfWarrantOrRightDomain" xlink:type="locator" xlink:label="us-gaap_ClassOfWarrantOrRightDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ClassOfWarrantOrRightAxis" xlink:type="locator" xlink:label="us-gaap_ClassOfWarrantOrRightAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ClassOfWarrantOrRightTable" xlink:type="locator" xlink:label="us-gaap_ClassOfWarrantOrRightTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_EquityAbstract" xlink:type="locator" xlink:label="us-gaap_EquityAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EquityAbstract" xlink:to="us-gaap_ClassOfWarrantOrRightTable" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfWarrantOrRightTable" xlink:to="us-gaap_ClassOfWarrantOrRightAxis" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfWarrantOrRightAxis" xlink:to="us-gaap_ClassOfWarrantOrRightDomain" order="10050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfWarrantOrRightDomain" xlink:to="arwr_WarrantOneMember" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfWarrantOrRightDomain" xlink:to="arwr_WarrantTwoMember" order="10090.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfWarrantOrRightDomain" xlink:to="arwr_WarrantThreeMember" order="10110.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfWarrantOrRightDomain" xlink:to="arwr_WarrantFourMember" order="10130.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfWarrantOrRightDomain" xlink:to="arwr_WarrantFiveMember" order="10150.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfWarrantOrRightDomain" xlink:to="arwr_WarrantSixMember" order="10170.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfWarrantOrRightDomain" xlink:to="arwr_WarrantSevenMember" order="10190.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfWarrantOrRightDomain" xlink:to="arwr_WarrantEightMember" order="10210.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfWarrantOrRightTable" xlink:to="us-gaap_ClassOfWarrantOrRightLineItems" order="10230.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfWarrantOrRightLineItems" xlink:to="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" order="10240.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfWarrantOrRightLineItems" xlink:to="us-gaap_ClassOfWarrantOrRightOutstanding" order="10600.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfWarrantOrRightLineItems" xlink:to="arwr_RemainingLifeOfWarrant" order="10980.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureCommitmentsAndContingenciesAdditionalInformationDetail" xlink:href="arwr-20150331.xsd#Role_DisclosureCommitmentsAndContingenciesAdditionalInformationDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureCommitmentsAndContingenciesAdditionalInformationDetail">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PurchaseObligationDueInNextTwelveMonths" xlink:type="locator" xlink:label="us-gaap_PurchaseObligationDueInNextTwelveMonths" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PurchaseObligationFutureMinimumPaymentsRemainderOfFiscalYear" xlink:type="locator" xlink:label="us-gaap_PurchaseObligationFutureMinimumPaymentsRemainderOfFiscalYear" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PurchaseObligation" xlink:type="locator" xlink:label="us-gaap_PurchaseObligation" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RetainedEarningsAppropriated" xlink:type="locator" xlink:label="us-gaap_RetainedEarningsAppropriated" />
    <loc xlink:href="arwr-20150331.xsd#arwr_FacilityAndEquipmentRentExpense" xlink:type="locator" xlink:label="arwr_FacilityAndEquipmentRentExpense" />
    <loc xlink:href="arwr-20150331.xsd#arwr_LeasedFacilityExpense" xlink:type="locator" xlink:label="arwr_LeasedFacilityExpense" />
    <loc xlink:href="arwr-20150331.xsd#arwr_PaymentsUnderCapitalLease" xlink:type="locator" xlink:label="arwr_PaymentsUnderCapitalLease" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_UtilitiesCosts" xlink:type="locator" xlink:label="us-gaap_UtilitiesCosts" />
    <loc xlink:href="arwr-20150331.xsd#arwr_OtherRentalExpenses" xlink:type="locator" xlink:label="arwr_OtherRentalExpenses" />
    <loc xlink:href="arwr-20150331.xsd#arwr_PercentageOfIncreaseInAnnualRentalCost" xlink:type="locator" xlink:label="arwr_PercentageOfIncreaseInAnnualRentalCost" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LeaseExpirationDate1" xlink:type="locator" xlink:label="us-gaap_LeaseExpirationDate1" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LeaseAndRentalExpense" xlink:type="locator" xlink:label="us-gaap_LeaseAndRentalExpense" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OtherCommitmentsLineItems" xlink:type="locator" xlink:label="us-gaap_OtherCommitmentsLineItems" />
    <loc xlink:href="arwr-20150331.xsd#arwr_ResearchFacilityInMadisonMember" xlink:type="locator" xlink:label="arwr_ResearchFacilityInMadisonMember" />
    <loc xlink:href="arwr-20150331.xsd#arwr_CorporateHeadquartersInPasadenaMember" xlink:type="locator" xlink:label="arwr_CorporateHeadquartersInPasadenaMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PropertySubjectToOrAvailableForOperatingLeaseDomain" xlink:type="locator" xlink:label="us-gaap_PropertySubjectToOrAvailableForOperatingLeaseDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis" xlink:type="locator" xlink:label="us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OtherCommitmentsTable" xlink:type="locator" xlink:label="us-gaap_OtherCommitmentsTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:type="locator" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:to="us-gaap_OtherCommitmentsTable" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OtherCommitmentsTable" xlink:to="us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis" xlink:to="us-gaap_PropertySubjectToOrAvailableForOperatingLeaseDomain" order="10050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertySubjectToOrAvailableForOperatingLeaseDomain" xlink:to="arwr_CorporateHeadquartersInPasadenaMember" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertySubjectToOrAvailableForOperatingLeaseDomain" xlink:to="arwr_ResearchFacilityInMadisonMember" order="10120.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OtherCommitmentsTable" xlink:to="us-gaap_OtherCommitmentsLineItems" order="10160.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OtherCommitmentsLineItems" xlink:to="us-gaap_LeaseAndRentalExpense" order="10170.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OtherCommitmentsLineItems" xlink:to="us-gaap_LeaseExpirationDate1" order="10210.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OtherCommitmentsLineItems" xlink:to="arwr_PercentageOfIncreaseInAnnualRentalCost" order="10250.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OtherCommitmentsLineItems" xlink:to="arwr_OtherRentalExpenses" order="10440.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OtherCommitmentsLineItems" xlink:to="us-gaap_UtilitiesCosts" order="10500.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OtherCommitmentsLineItems" xlink:to="arwr_PaymentsUnderCapitalLease" order="10560.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OtherCommitmentsLineItems" xlink:to="arwr_LeasedFacilityExpense" order="10620.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OtherCommitmentsLineItems" xlink:to="arwr_FacilityAndEquipmentRentExpense" order="10710.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OtherCommitmentsLineItems" xlink:to="us-gaap_RetainedEarningsAppropriated" order="10900.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OtherCommitmentsLineItems" xlink:to="us-gaap_PurchaseObligation" order="10970.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OtherCommitmentsLineItems" xlink:to="us-gaap_PurchaseObligationFutureMinimumPaymentsRemainderOfFiscalYear" order="11010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OtherCommitmentsLineItems" xlink:to="us-gaap_PurchaseObligationDueInNextTwelveMonths" order="11050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureCommitmentsAndContingenciesFutureMinimumLeasePaymentsUnderCapitalizedLeasesDetail" xlink:href="arwr-20150331.xsd#Role_DisclosureCommitmentsAndContingenciesFutureMinimumLeasePaymentsUnderCapitalizedLeasesDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureCommitmentsAndContingenciesFutureMinimumLeasePaymentsUnderCapitalizedLeasesDetail">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CapitalLeaseObligationsNoncurrent" xlink:type="locator" xlink:label="us-gaap_CapitalLeaseObligationsNoncurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CapitalLeaseObligationsCurrent" xlink:type="locator" xlink:label="us-gaap_CapitalLeaseObligationsCurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CapitalLeasesFutureMinimumPaymentsPresentValueOfNetMinimumPayments" xlink:type="locator" xlink:label="us-gaap_CapitalLeasesFutureMinimumPaymentsPresentValueOfNetMinimumPayments" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CapitalLeasesFutureMinimumPaymentsInterestIncludedInPayments" xlink:type="locator" xlink:label="us-gaap_CapitalLeasesFutureMinimumPaymentsInterestIncludedInPayments" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CapitalLeasesFutureMinimumPaymentsDueThereafter" xlink:type="locator" xlink:label="us-gaap_CapitalLeasesFutureMinimumPaymentsDueThereafter" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CapitalLeasesFutureMinimumPaymentsDueInFourYears" xlink:type="locator" xlink:label="us-gaap_CapitalLeasesFutureMinimumPaymentsDueInFourYears" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CapitalLeasesFutureMinimumPaymentsDueInThreeYears" xlink:type="locator" xlink:label="us-gaap_CapitalLeasesFutureMinimumPaymentsDueInThreeYears" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CapitalLeasesFutureMinimumPaymentsDueInTwoYears" xlink:type="locator" xlink:label="us-gaap_CapitalLeasesFutureMinimumPaymentsDueInTwoYears" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CapitalLeasesFutureMinimumPaymentsDueCurrent" xlink:type="locator" xlink:label="us-gaap_CapitalLeasesFutureMinimumPaymentsDueCurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CapitalLeasesFutureMinimumPaymentsRemainderOfFiscalYear" xlink:type="locator" xlink:label="us-gaap_CapitalLeasesFutureMinimumPaymentsRemainderOfFiscalYear" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LeasesAbstract" xlink:type="locator" xlink:label="us-gaap_LeasesAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeasesAbstract" xlink:to="us-gaap_CapitalLeasesFutureMinimumPaymentsRemainderOfFiscalYear" order="10080.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeasesAbstract" xlink:to="us-gaap_CapitalLeasesFutureMinimumPaymentsDueCurrent" order="10120.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeasesAbstract" xlink:to="us-gaap_CapitalLeasesFutureMinimumPaymentsDueInTwoYears" order="10160.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeasesAbstract" xlink:to="us-gaap_CapitalLeasesFutureMinimumPaymentsDueInThreeYears" order="10200.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeasesAbstract" xlink:to="us-gaap_CapitalLeasesFutureMinimumPaymentsDueInFourYears" order="10240.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeasesAbstract" xlink:to="us-gaap_CapitalLeasesFutureMinimumPaymentsDueThereafter" order="10280.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeasesAbstract" xlink:to="us-gaap_CapitalLeasesFutureMinimumPaymentsInterestIncludedInPayments" order="10300.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeasesAbstract" xlink:to="us-gaap_CapitalLeasesFutureMinimumPaymentsPresentValueOfNetMinimumPayments" order="10340.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeasesAbstract" xlink:to="us-gaap_CapitalLeaseObligationsCurrent" order="10380.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeasesAbstract" xlink:to="us-gaap_CapitalLeaseObligationsNoncurrent" order="10400.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureCommitmentsAndContingenciesFutureMinimumLeasePaymentsUnderOperatingLeasesDetail" xlink:href="arwr-20150331.xsd#Role_DisclosureCommitmentsAndContingenciesFutureMinimumLeasePaymentsUnderOperatingLeasesDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureCommitmentsAndContingenciesFutureMinimumLeasePaymentsUnderOperatingLeasesDetail">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDue" xlink:type="locator" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDue" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueThereafter" xlink:type="locator" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueThereafter" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears" xlink:type="locator" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears" xlink:type="locator" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears" xlink:type="locator" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent" xlink:type="locator" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsRemainderOfFiscalYear" xlink:type="locator" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsRemainderOfFiscalYear" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LeasesAbstract" xlink:type="locator" xlink:label="us-gaap_LeasesAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeasesAbstract" xlink:to="us-gaap_OperatingLeasesFutureMinimumPaymentsRemainderOfFiscalYear" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeasesAbstract" xlink:to="us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent" order="10110.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeasesAbstract" xlink:to="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears" order="10150.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeasesAbstract" xlink:to="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears" order="10190.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeasesAbstract" xlink:to="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears" order="10230.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeasesAbstract" xlink:to="us-gaap_OperatingLeasesFutureMinimumPaymentsDueThereafter" order="10270.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeasesAbstract" xlink:to="us-gaap_OperatingLeasesFutureMinimumPaymentsDue" order="10290.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureStockBasedCompensationAdditionalInformationDetail" xlink:href="arwr-20150331.xsd#Role_DisclosureStockBasedCompensationAdditionalInformationDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureStockBasedCompensationAdditionalInformationDetail">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions" xlink:type="locator" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDescription" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDescription" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:type="locator" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions" xlink:type="locator" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue" />
    <loc xlink:href="arwr-20150331.xsd#arwr_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodFairValue" xlink:type="locator" xlink:label="arwr_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodFairValue" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpense" xlink:type="locator" xlink:label="us-gaap_AllocatedShareBasedCompensationExpense" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod" />
    <loc xlink:href="arwr-20150331.xsd#arwr_ShareBasedCompensationArrangementByShareBasedPaymentAwardInducementGrants" xlink:type="locator" xlink:label="arwr_ShareBasedCompensationArrangementByShareBasedPaymentAwardInducementGrants" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CommonStockCapitalSharesReservedForFutureIssuance" xlink:type="locator" xlink:label="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RestrictedStockUnitsRSUMember" xlink:type="locator" xlink:label="us-gaap_RestrictedStockUnitsRSUMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_EmployeeStockOptionMember" xlink:type="locator" xlink:label="us-gaap_EmployeeStockOptionMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AwardTypeAxis" xlink:type="locator" xlink:label="us-gaap_AwardTypeAxis" />
    <loc xlink:href="arwr-20150331.xsd#arwr_TwoThousandsStockOptionPlanMember" xlink:type="locator" xlink:label="arwr_TwoThousandsStockOptionPlanMember" />
    <loc xlink:href="arwr-20150331.xsd#arwr_OutsideOfEquityCompensationPlansMember" xlink:type="locator" xlink:label="arwr_OutsideOfEquityCompensationPlansMember" />
    <loc xlink:href="arwr-20150331.xsd#arwr_TwoThousandsThirteenIncentivePlanMember" xlink:type="locator" xlink:label="arwr_TwoThousandsThirteenIncentivePlanMember" />
    <loc xlink:href="arwr-20150331.xsd#arwr_TwoThousandsFourEquityIncentivePlanMember" xlink:type="locator" xlink:label="arwr_TwoThousandsFourEquityIncentivePlanMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PlanNameDomain" xlink:type="locator" xlink:label="us-gaap_PlanNameDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PlanNameAxis" xlink:type="locator" xlink:label="us-gaap_PlanNameAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:type="locator" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:type="locator" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_PlanNameAxis" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PlanNameAxis" xlink:to="us-gaap_PlanNameDomain" order="10050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PlanNameDomain" xlink:to="arwr_TwoThousandsFourEquityIncentivePlanMember" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PlanNameDomain" xlink:to="arwr_TwoThousandsThirteenIncentivePlanMember" order="10090.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PlanNameDomain" xlink:to="arwr_OutsideOfEquityCompensationPlansMember" order="10110.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PlanNameDomain" xlink:to="arwr_TwoThousandsStockOptionPlanMember" order="10130.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_AwardTypeAxis" order="10030.02" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AwardTypeAxis" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" order="10160.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="us-gaap_EmployeeStockOptionMember" order="10180.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="us-gaap_RestrictedStockUnitsRSUMember" order="10200.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" order="10950.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance" order="10960.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" order="11100.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" order="11240.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber" order="11360.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" order="11720.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="arwr_ShareBasedCompensationArrangementByShareBasedPaymentAwardInducementGrants" order="12080.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod" order="12820.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_AllocatedShareBasedCompensationExpense" order="12970.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="arwr_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodFairValue" order="13160.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue" order="13350.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions" order="13540.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" order="13620.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" order="13730.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDescription" order="14060.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions" order="14380.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureStockBasedCompensationSummarizeInformationAboutStockOptionsDetail" xlink:href="arwr-20150331.xsd#Role_DisclosureStockBasedCompensationSummarizeInformationAboutStockOptionsDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureStockBasedCompensationSummarizeInformationAboutStockOptionsDetail">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1" xlink:type="locator" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" xlink:type="locator" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" xlink:type="locator" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_li0l2" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_li0l2" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:type="locator" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" order="10130.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod" order="10250.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" order="10370.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_li0l2" order="10490.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" order="11090.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" order="11210.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" order="11330.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice" order="11450.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" order="11570.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_li0l2" order="11690.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" order="12290.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" order="12410.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" order="12530.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" order="12650.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1" order="12690.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureStockBasedCompensationAssumptionsUsedToValueStockOptionsDetail" xlink:href="arwr-20150331.xsd#Role_DisclosureStockBasedCompensationAssumptionsUsedToValueStockOptionsDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureStockBasedCompensationAssumptionsUsedToValueStockOptionsDetail">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:type="locator" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMaximum" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMaximum" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMinimum" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMinimum" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_MaximumMember" xlink:type="locator" xlink:label="us-gaap_MaximumMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_MinimumMember" xlink:type="locator" xlink:label="us-gaap_MinimumMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RangeMember" xlink:type="locator" xlink:label="us-gaap_RangeMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RangeAxis" xlink:type="locator" xlink:label="us-gaap_RangeAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:type="locator" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:type="locator" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_RangeAxis" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RangeAxis" xlink:to="us-gaap_RangeMember" order="10050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RangeMember" xlink:to="us-gaap_MinimumMember" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RangeMember" xlink:to="us-gaap_MaximumMember" order="10090.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" order="10110.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" order="10120.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" order="10160.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMinimum" order="10200.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMaximum" order="10280.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" order="10360.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" order="10440.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" order="10600.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfRestrictedStockActivityDetail" xlink:href="arwr-20150331.xsd#Role_DisclosureStockBasedCompensationSummaryOfRestrictedStockActivityDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfRestrictedStockActivityDetail">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_li0l2" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_li0l2" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RestrictedStockUnitsRSUMember" xlink:type="locator" xlink:label="us-gaap_RestrictedStockUnitsRSUMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AwardTypeAxis" xlink:type="locator" xlink:label="us-gaap_AwardTypeAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:type="locator" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:type="locator" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_AwardTypeAxis" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AwardTypeAxis" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" order="10050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="us-gaap_RestrictedStockUnitsRSUMember" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" order="10140.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" order="10150.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" order="10210.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" order="10290.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" order="10350.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_li0l2" order="10410.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" order="10800.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" order="10860.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" order="10940.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" order="11000.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_li0l2" order="11060.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureFairValueMeasurementsFairValueMeasurementsForAssetsAndLiabilitiesMeasuredAtFairValueOnRecurringBasisDetail" xlink:href="arwr-20150331.xsd#Role_DisclosureFairValueMeasurementsFairValueMeasurementsForAssetsAndLiabilitiesMeasuredAtFairValueOnRecurringBasisDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureFairValueMeasurementsFairValueMeasurementsForAssetsAndLiabilitiesMeasuredAtFairValueOnRecurringBasisDetail">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability" xlink:type="locator" xlink:label="us-gaap_BusinessCombinationContingentConsiderationLiability" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DerivativeLiabilitiesCurrent" xlink:type="locator" xlink:label="us-gaap_DerivativeLiabilitiesCurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CashAndCashEquivalentsFairValueDisclosure" xlink:type="locator" xlink:label="us-gaap_CashAndCashEquivalentsFairValueDisclosure" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:type="locator" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueInputsLevel3Member" xlink:type="locator" xlink:label="us-gaap_FairValueInputsLevel3Member" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueInputsLevel2Member" xlink:type="locator" xlink:label="us-gaap_FairValueInputsLevel2Member" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueInputsLevel1Member" xlink:type="locator" xlink:label="us-gaap_FairValueInputsLevel1Member" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:type="locator" xlink:label="us-gaap_FairValueByFairValueHierarchyLevelAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueMeasurementsRecurringMember" xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementsRecurringMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain" xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementFrequencyDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueByMeasurementFrequencyAxis" xlink:type="locator" xlink:label="us-gaap_FairValueByMeasurementFrequencyAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:type="locator" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueDisclosuresAbstract" xlink:type="locator" xlink:label="us-gaap_FairValueDisclosuresAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="us-gaap_FairValueByMeasurementFrequencyAxis" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueByMeasurementFrequencyAxis" xlink:to="us-gaap_FairValueMeasurementFrequencyDomain" order="10050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueMeasurementFrequencyDomain" xlink:to="us-gaap_FairValueMeasurementsRecurringMember" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="us-gaap_FairValueByFairValueHierarchyLevelAxis" order="10030.02" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:to="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" order="10160.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:to="us-gaap_FairValueInputsLevel1Member" order="10180.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:to="us-gaap_FairValueInputsLevel2Member" order="10200.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:to="us-gaap_FairValueInputsLevel3Member" order="10220.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" order="10440.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="us-gaap_CashAndCashEquivalentsFairValueDisclosure" order="10450.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="us-gaap_DerivativeLiabilitiesCurrent" order="10590.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="us-gaap_BusinessCombinationContingentConsiderationLiability" order="10730.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureFairValueMeasurementsAdditionalInformationDetail" xlink:href="arwr-20150331.xsd#Role_DisclosureFairValueMeasurementsAdditionalInformationDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureFairValueMeasurementsAdditionalInformationDetail">
    <loc xlink:href="arwr-20150331.xsd#arwr_NumberOfExchangeRightAreSold" xlink:type="locator" xlink:label="arwr_NumberOfExchangeRightAreSold" />
    <loc xlink:href="arwr-20150331.xsd#arwr_ExchangeRightConvertibleConversionRatioForFiveYear" xlink:type="locator" xlink:label="arwr_ExchangeRightConvertibleConversionRatioForFiveYear" />
    <loc xlink:href="arwr-20150331.xsd#arwr_ExchangeRightConvertibleConversionRatioForFourYear" xlink:type="locator" xlink:label="arwr_ExchangeRightConvertibleConversionRatioForFourYear" />
    <loc xlink:href="arwr-20150331.xsd#arwr_ExchangeRightConvertibleConversionRatioForThreeYear" xlink:type="locator" xlink:label="arwr_ExchangeRightConvertibleConversionRatioForThreeYear" />
    <loc xlink:href="arwr-20150331.xsd#arwr_ExchangeRightConvertibleConversionRatioForTwoYear" xlink:type="locator" xlink:label="arwr_ExchangeRightConvertibleConversionRatioForTwoYear" />
    <loc xlink:href="arwr-20150331.xsd#arwr_ExchangeRightConvertibleConversionRatioForFirstYear" xlink:type="locator" xlink:label="arwr_ExchangeRightConvertibleConversionRatioForFirstYear" />
    <loc xlink:href="arwr-20150331.xsd#arwr_TermOfExchangeRights" xlink:type="locator" xlink:label="arwr_TermOfExchangeRights" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings" xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ClassOfWarrantOrRightOutstanding" xlink:type="locator" xlink:label="us-gaap_ClassOfWarrantOrRightOutstanding" />
    <loc xlink:href="arwr-20150331.xsd#arwr_WarrantsIssuedToAcquireCommonStock" xlink:type="locator" xlink:label="arwr_WarrantsIssuedToAcquireCommonStock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_HeldToMaturitySecuritiesFairValue" xlink:type="locator" xlink:label="us-gaap_HeldToMaturitySecuritiesFairValue" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_HeldToMaturitySecurities" xlink:type="locator" xlink:label="us-gaap_HeldToMaturitySecurities" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_HeldToMaturitySecuritiesNoncurrent" xlink:type="locator" xlink:label="us-gaap_HeldToMaturitySecuritiesNoncurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_HeldToMaturitySecuritiesCurrent" xlink:type="locator" xlink:label="us-gaap_HeldToMaturitySecuritiesCurrent" />
    <loc xlink:href="arwr-20150331.xsd#arwr_FairValueMeasurementsDisclosureLineItems" xlink:type="locator" xlink:label="arwr_FairValueMeasurementsDisclosureLineItems" />
    <loc xlink:href="arwr-20150331.xsd#arwr_AblarisTherapeuticsMember" xlink:type="locator" xlink:label="arwr_AblarisTherapeuticsMember" />
    <loc xlink:href="arwr-20150331.xsd#arwr_TwoThousandThirteenWarrantMember" xlink:type="locator" xlink:label="arwr_TwoThousandThirteenWarrantMember" />
    <loc xlink:href="arwr-20150331.xsd#arwr_TwoThousandTwelveWarrantMember" xlink:type="locator" xlink:label="arwr_TwoThousandTwelveWarrantMember" />
    <loc xlink:href="arwr-20150331.xsd#arwr_TwoThousandTenWarrantMember" xlink:type="locator" xlink:label="arwr_TwoThousandTenWarrantMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ClassOfWarrantOrRightDomain" xlink:type="locator" xlink:label="us-gaap_ClassOfWarrantOrRightDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ClassOfWarrantOrRightAxis" xlink:type="locator" xlink:label="us-gaap_ClassOfWarrantOrRightAxis" />
    <loc xlink:href="arwr-20150331.xsd#arwr_FairValueMeasurementsDisclosureTable" xlink:type="locator" xlink:label="arwr_FairValueMeasurementsDisclosureTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueDisclosuresAbstract" xlink:type="locator" xlink:label="us-gaap_FairValueDisclosuresAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="arwr_FairValueMeasurementsDisclosureTable" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FairValueMeasurementsDisclosureTable" xlink:to="us-gaap_ClassOfWarrantOrRightAxis" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfWarrantOrRightAxis" xlink:to="us-gaap_ClassOfWarrantOrRightDomain" order="10050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfWarrantOrRightDomain" xlink:to="arwr_TwoThousandTenWarrantMember" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfWarrantOrRightDomain" xlink:to="arwr_TwoThousandTwelveWarrantMember" order="10110.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfWarrantOrRightDomain" xlink:to="arwr_TwoThousandThirteenWarrantMember" order="10150.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfWarrantOrRightDomain" xlink:to="arwr_AblarisTherapeuticsMember" order="10220.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FairValueMeasurementsDisclosureTable" xlink:to="arwr_FairValueMeasurementsDisclosureLineItems" order="10440.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FairValueMeasurementsDisclosureLineItems" xlink:to="us-gaap_HeldToMaturitySecuritiesCurrent" order="10450.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FairValueMeasurementsDisclosureLineItems" xlink:to="us-gaap_HeldToMaturitySecuritiesNoncurrent" order="10470.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FairValueMeasurementsDisclosureLineItems" xlink:to="us-gaap_HeldToMaturitySecurities" order="10490.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FairValueMeasurementsDisclosureLineItems" xlink:to="us-gaap_HeldToMaturitySecuritiesFairValue" order="10510.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FairValueMeasurementsDisclosureLineItems" xlink:to="arwr_WarrantsIssuedToAcquireCommonStock" order="10560.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FairValueMeasurementsDisclosureLineItems" xlink:to="us-gaap_ClassOfWarrantOrRightOutstanding" order="10620.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FairValueMeasurementsDisclosureLineItems" xlink:to="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings" order="10920.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FairValueMeasurementsDisclosureLineItems" xlink:to="arwr_TermOfExchangeRights" order="11190.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FairValueMeasurementsDisclosureLineItems" xlink:to="arwr_ExchangeRightConvertibleConversionRatioForFirstYear" order="11250.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FairValueMeasurementsDisclosureLineItems" xlink:to="arwr_ExchangeRightConvertibleConversionRatioForTwoYear" order="11310.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FairValueMeasurementsDisclosureLineItems" xlink:to="arwr_ExchangeRightConvertibleConversionRatioForThreeYear" order="11370.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FairValueMeasurementsDisclosureLineItems" xlink:to="arwr_ExchangeRightConvertibleConversionRatioForFourYear" order="11430.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FairValueMeasurementsDisclosureLineItems" xlink:to="arwr_ExchangeRightConvertibleConversionRatioForFiveYear" order="11490.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FairValueMeasurementsDisclosureLineItems" xlink:to="arwr_NumberOfExchangeRightAreSold" order="11550.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureFairValueMeasurementsAssumptionsUsedInValuingDerivativeLiabilitiesDetail" xlink:href="arwr-20150331.xsd#Role_DisclosureFairValueMeasurementsAssumptionsUsedInValuingDerivativeLiabilitiesDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureFairValueMeasurementsAssumptionsUsedInValuingDerivativeLiabilitiesDetail">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueAssumptionsExpectedVolatilityRate" xlink:type="locator" xlink:label="us-gaap_FairValueAssumptionsExpectedVolatilityRate" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueAssumptionsExpectedDividendRate" xlink:type="locator" xlink:label="us-gaap_FairValueAssumptionsExpectedDividendRate" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueAssumptionsExpectedTerm" xlink:type="locator" xlink:label="us-gaap_FairValueAssumptionsExpectedTerm" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueAssumptionsRiskFreeInterestRate" xlink:type="locator" xlink:label="us-gaap_FairValueAssumptionsRiskFreeInterestRate" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" xlink:type="locator" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" />
    <loc xlink:href="arwr-20150331.xsd#arwr_ExchangeRightsMember" xlink:type="locator" xlink:label="arwr_ExchangeRightsMember" />
    <loc xlink:href="arwr-20150331.xsd#arwr_TwoThousandThirteenWarrantMember" xlink:type="locator" xlink:label="arwr_TwoThousandThirteenWarrantMember" />
    <loc xlink:href="arwr-20150331.xsd#arwr_TwoThousandTwelveWarrantMember" xlink:type="locator" xlink:label="arwr_TwoThousandTwelveWarrantMember" />
    <loc xlink:href="arwr-20150331.xsd#arwr_TwoThousandTenWarrantMember" xlink:type="locator" xlink:label="arwr_TwoThousandTenWarrantMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:type="locator" xlink:label="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueByLiabilityClassAxis" xlink:type="locator" xlink:label="us-gaap_FairValueByLiabilityClassAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" xlink:type="locator" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueDisclosuresAbstract" xlink:type="locator" xlink:label="us-gaap_FairValueDisclosuresAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" xlink:to="us-gaap_FairValueByLiabilityClassAxis" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueByLiabilityClassAxis" xlink:to="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" order="10050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:to="arwr_TwoThousandTenWarrantMember" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:to="arwr_TwoThousandTwelveWarrantMember" order="10150.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:to="arwr_TwoThousandThirteenWarrantMember" order="10230.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:to="arwr_ExchangeRightsMember" order="10340.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" order="10420.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" xlink:to="us-gaap_FairValueAssumptionsRiskFreeInterestRate" order="10430.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" xlink:to="us-gaap_FairValueAssumptionsExpectedTerm" order="10510.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" xlink:to="us-gaap_FairValueAssumptionsExpectedDividendRate" order="10590.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" xlink:to="us-gaap_FairValueAssumptionsExpectedVolatilityRate" order="10670.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureFairValueMeasurementsReconciliationOfDerivativeLiabilityDetail" xlink:href="arwr-20150331.xsd#Role_DisclosureFairValueMeasurementsReconciliationOfDerivativeLiabilityDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureFairValueMeasurementsReconciliationOfDerivativeLiabilityDetail">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue" xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_li0l2" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements" xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings" xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityIssues" xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityIssues" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue" xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" xlink:type="locator" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" />
    <loc xlink:href="arwr-20150331.xsd#arwr_ExchangeRightsMember" xlink:type="locator" xlink:label="arwr_ExchangeRightsMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:type="locator" xlink:label="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueByLiabilityClassAxis" xlink:type="locator" xlink:label="us-gaap_FairValueByLiabilityClassAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_WarrantMember" xlink:type="locator" xlink:label="us-gaap_WarrantMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:type="locator" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FinancialInstrumentAxis" xlink:type="locator" xlink:label="us-gaap_FinancialInstrumentAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" xlink:type="locator" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueDisclosuresAbstract" xlink:type="locator" xlink:label="us-gaap_FairValueDisclosuresAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" xlink:to="us-gaap_FinancialInstrumentAxis" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancialInstrumentAxis" xlink:to="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" order="10050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="us-gaap_WarrantMember" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" xlink:to="us-gaap_FairValueByLiabilityClassAxis" order="10030.02" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueByLiabilityClassAxis" xlink:to="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" order="10100.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:to="arwr_ExchangeRightsMember" order="10120.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" order="10140.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" xlink:to="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue" order="10150.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" xlink:to="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityIssues" order="10210.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" xlink:to="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings" order="10250.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" xlink:to="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements" order="10310.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" xlink:to="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_li0l2" order="10370.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureFairValueMeasurementsChangeInFairValueOfContingentConsiderationObligationsDetail" xlink:href="arwr-20150331.xsd#Role_DisclosureFairValueMeasurementsChangeInFairValueOfContingentConsiderationObligationsDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20150331/taxonomy/role/DisclosureFairValueMeasurementsChangeInFairValueOfContingentConsiderationObligationsDetail">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability" xlink:type="locator" xlink:label="us-gaap_BusinessCombinationContingentConsiderationLiability_li0l2" />
    <loc xlink:href="arwr-20150331.xsd#arwr_BusinessCombinationFairValueOfChangeInContingentConsideration" xlink:type="locator" xlink:label="arwr_BusinessCombinationFairValueOfChangeInContingentConsideration" />
    <loc xlink:href="arwr-20150331.xsd#arwr_BusinessCombinationContingentConsiderationPayments" xlink:type="locator" xlink:label="arwr_BusinessCombinationContingentConsiderationPayments" />
    <loc xlink:href="arwr-20150331.xsd#arwr_BusinessCombinationPurchasePriceContingentConsiderationFairValue" xlink:type="locator" xlink:label="arwr_BusinessCombinationPurchasePriceContingentConsiderationFairValue" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability" xlink:type="locator" xlink:label="us-gaap_BusinessCombinationContingentConsiderationLiability" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BusinessCombinationsAbstract" xlink:type="locator" xlink:label="us-gaap_BusinessCombinationsAbstract" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueDisclosuresAbstract" xlink:type="locator" xlink:label="us-gaap_FairValueDisclosuresAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="us-gaap_BusinessCombinationsAbstract" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationsAbstract" xlink:to="us-gaap_BusinessCombinationContingentConsiderationLiability" order="10090.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationsAbstract" xlink:to="arwr_BusinessCombinationPurchasePriceContingentConsiderationFairValue" order="10150.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationsAbstract" xlink:to="arwr_BusinessCombinationContingentConsiderationPayments" order="10190.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationsAbstract" xlink:to="arwr_BusinessCombinationFairValueOfChangeInContingentConsideration" order="10230.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationsAbstract" xlink:to="us-gaap_BusinessCombinationContingentConsiderationLiability_li0l2" order="10290.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" />
  </presentationLink>
</linkbase>
