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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 MfQA2npzsQHc5IEmLzvwSV4mnK/c4faqjs0IovfMt8FnjFHdS7uUXEcSRJUkvXX+
 BoaCG+FXtYw5TZlO9vZ1tg==

<SEC-DOCUMENT>0001140361-10-010360.txt : 20100305
<SEC-HEADER>0001140361-10-010360.hdr.sgml : 20100305
<ACCEPTANCE-DATETIME>20100305171048
ACCESSION NUMBER:		0001140361-10-010360
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20100303
FILED AS OF DATE:		20100305
DATE AS OF CHANGE:		20100305

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Hendry Gregory L
		CENTRAL INDEX KEY:			0001486334

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-34416
		FILM NUMBER:		10661560

	MAIL ADDRESS:	
		STREET 1:		3300 LAKE AVENUE
		CITY:			ALTADENA
		STATE:			CA
		ZIP:			91001

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			PennyMac Mortgage Investment Trust
		CENTRAL INDEX KEY:			0001464423
		STANDARD INDUSTRIAL CLASSIFICATION:	REAL ESTATE INVESTMENT TRUSTS [6798]
		IRS NUMBER:				270186273
		STATE OF INCORPORATION:			MD
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		27001 AGOURA ROAD
		STREET 2:		THIRD FLOOR
		CITY:			CALABASAS
		STATE:			CA
		ZIP:			91301
		BUSINESS PHONE:		(818) 224-7442

	MAIL ADDRESS:	
		STREET 1:		27001 AGOURA ROAD
		STREET 2:		THIRD FLOOR
		CITY:			CALABASAS
		STATE:			CA
		ZIP:			91301
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>doc1.xml
<DESCRIPTION>FORM 3
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0203</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2010-03-03</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001464423</issuerCik>
        <issuerName>PennyMac Mortgage Investment Trust</issuerName>
        <issuerTradingSymbol>PMT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001486334</rptOwnerCik>
            <rptOwnerName>Hendry Gregory L</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O PENNYMAC MORTGAGE INVESTMENT TRUST</rptOwnerStreet1>
            <rptOwnerStreet2>2700 AGOURA ROAD</rptOwnerStreet2>
            <rptOwnerCity>CALABASAS</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>91301</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chief Accounting Officer</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Shares of Beneficial Interest</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1440</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Mr. Hendry was granted 1,440 restricted share units upon the completion of the Company's initial public offering on August 4, 2009. The restricted share units, which vest in four equal annual installments beginning on the first anniversary of the grant date, are to be settled in an equal number of common shares of beneficial interest upon vesting.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Gregory L. Hendry</signatureName>
        <signatureDate>2010-03-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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