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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,
 VAmPchVxkNFVafvC08gmbLbtWs52MC9ZtIbQ7f8kb7ag693nlwN3IUetudHjz3sf
 XQ5Koi84h0YzVAnbf2ePrg==

<SEC-DOCUMENT>0000018230-04-000043.txt : 20040120
<SEC-HEADER>0000018230-04-000043.hdr.sgml : 20040119
<ACCEPTANCE-DATETIME>20040120115510
ACCESSION NUMBER:		0000018230-04-000043
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20040120
FILED AS OF DATE:		20040120

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			BAHAJ ALI M
		CENTRAL INDEX KEY:			0001172565

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-00768
		FILM NUMBER:		04531651

	BUSINESS ADDRESS:	
		STREET 1:		100 N E ADAMS STREET
		CITY:			PEORIA
		STATE:			IL
		ZIP:			61629
		BUSINESS PHONE:		3096754610

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CATERPILLAR INC
		CENTRAL INDEX KEY:			0000018230
		STANDARD INDUSTRIAL CLASSIFICATION:	CONSTRUCTION MACHINERY & EQUIP [3531]
		IRS NUMBER:				370602744
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		100 NE ADAMS ST
		CITY:			PEORIA
		STATE:			IL
		ZIP:			61629
		BUSINESS PHONE:		3096751000

	MAIL ADDRESS:	
		STREET 1:		100 NE ADAMS ST
		CITY:			PEORIA
		STATE:			IL
		ZIP:			61629

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	CATERPILLAR TRACTOR CO
		DATE OF NAME CHANGE:	19860623
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType><periodOfReport>2004-01-20</periodOfReport>
    <issuer>
        <issuerCik>0000018230</issuerCik>
        <issuerName>CATERPILLAR INC</issuerName>
        <issuerTradingSymbol>CAT</issuerTradingSymbol></issuer><reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001172565</rptOwnerCik>
            <rptOwnerName>BAHAJ ALI M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>100 N.E. ADAMS STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>PEORIA</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>61629-3305</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>0</isDirector><isOfficer>1</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther><officerTitle>Vice President</officerTitle></reportingOwnerRelationship></reportingOwner><nonDerivativeTable><nonDerivativeTransaction><securityTitle><value>Common</value></securityTitle><transactionDate><value>2004-01-20</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>F</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>63</value></transactionShares><transactionPricePerShare><value>83.11</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>D</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>13170</value><footnoteId id="F1"/></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><nature
OfOwnership><value/></natureOfOwnership></ownershipNature></nonDerivativeTransaction><nonDerivativeHolding><securityTitle><value>Common</value></securityTitle><postTransactionAmounts><sharesOwnedFollowingTransaction><value>195</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>I</value></directOrIndirectOwnership><natureOfOwnership><value>Owned by Wife</value><footnoteId id="F2"/></natureOfOwnership></ownershipNature></nonDerivativeHolding></nonDerivativeTable><footnotes><footnote id="F1">This amount includes 8543 shares in EIP-1, 34 shares in SEIP and 42 shares in dividend reinvestment.</footnote><footnote id="F2">Reporting person disclaims beneficial ownership.</footnote></footnotes><remarks/><ownerSignature><signatureName>Ali M. Bahaj; L.J. Huxtable, POA</signatureName><signatureDate>2004-01-20</signatureDate></ownerSignature></ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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