<SEC-DOCUMENT>0001209191-12-007613.txt : 20120203
<SEC-HEADER>0001209191-12-007613.hdr.sgml : 20120203
<ACCEPTANCE-DATETIME>20120203182650
ACCESSION NUMBER:		0001209191-12-007613
CONFORMED SUBMISSION TYPE:	5/A
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20111231
FILED AS OF DATE:		20120203
DATE AS OF CHANGE:		20120203

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Porzenheim Clifford J
		CENTRAL INDEX KEY:			0001383131

	FILING VALUES:
		FORM TYPE:		5/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-02328
		FILM NUMBER:		12571539

	MAIL ADDRESS:	
		STREET 1:		500 WEST MONROE STREET
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60661

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			GATX CORP
		CENTRAL INDEX KEY:			0000040211
		STANDARD INDUSTRIAL CLASSIFICATION:	TRANSPORTATION SERVICES [4700]
		IRS NUMBER:				361124040
		STATE OF INCORPORATION:			NY
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		222 WEST ADAMS STREET
		CITY:			CHICAGO
		STATE:			X1
		ZIP:			60606-5314
		BUSINESS PHONE:		3126216200

	MAIL ADDRESS:	
		STREET 1:		222 WEST ADAMS STREET
		CITY:			CHICAGO
		STATE:			X1
		ZIP:			60606-5314

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	GENERAL AMERICAN TRANSPORTATION CORP
		DATE OF NAME CHANGE:	19750722
</SEC-HEADER>
<DOCUMENT>
<TYPE>5/A
<SEQUENCE>1
<FILENAME>c27079_5ax0.xml
<DESCRIPTION>MAIN DOCUMENT DESCRIPTION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0304</schemaVersion>

    <documentType>5/A</documentType>

    <periodOfReport>2011-12-31</periodOfReport>

    <dateOfOriginalSubmission>2012-01-26</dateOfOriginalSubmission>

    <form3HoldingsReported>0</form3HoldingsReported>

    <form4TransactionsReported>1</form4TransactionsReported>

    <issuer>
        <issuerCik>0000040211</issuerCik>
        <issuerName>GATX CORP</issuerName>
        <issuerTradingSymbol>GMT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001383131</rptOwnerCik>
            <rptOwnerName>Porzenheim Clifford J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>222 W. ADAMS ST.</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>CHICAGO</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60606</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Sr. VP Strategic Growth</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2011-02-25</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1579</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>19062.8695</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <ownerSignature>
        <signatureName>Lisa M. Ibarra, by Power of Attorney on behalf of Clifford J. Porzenheim</signatureName>
        <signatureDate>2012-02-03</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
