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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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 NphWqQXxkBYbb4UNiywQAQ==

<SEC-DOCUMENT>0001104659-09-047352.txt : 20090805
<SEC-HEADER>0001104659-09-047352.hdr.sgml : 20090805
<ACCEPTANCE-DATETIME>20090805160036
ACCESSION NUMBER:		0001104659-09-047352
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20090804
FILED AS OF DATE:		20090805
DATE AS OF CHANGE:		20090805

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Chang Andrew S
		CENTRAL INDEX KEY:			0001468932

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-34416
		FILM NUMBER:		09988254

	MAIL ADDRESS:	
		STREET 1:		2940 NEILSON WAY
		STREET 2:		UNIT 103
		CITY:			SANTA MONICA
		STATE:			CA
		ZIP:			90405

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>4
<SEQUENCE>1
<FILENAME>a4.xml
<DESCRIPTION>4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2009-08-04</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001468932</rptOwnerCik>
            <rptOwnerName>Chang Andrew S</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O PENNYMAC MORTGAGE INVESTMENT TRUST</rptOwnerStreet1>
            <rptOwnerStreet2>27001 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 Business Development Ofc</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Shares of Beneficial Interest</value>
            </securityTitle>
            <transactionDate>
                <value>2009-08-04</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>20000</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>20000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Mr. Chang was granted 20,000 restricted share units upon the completion of the Company's initial public offering.  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>

    <ownerSignature>
        <signatureName>/s/ Andrew S. Chang</signatureName>
        <signatureDate>2009-08-04</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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