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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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<SEC-DOCUMENT>0000899171-06-000033.txt : 20060518
<SEC-HEADER>0000899171-06-000033.hdr.sgml : 20060518
<ACCEPTANCE-DATETIME>20060518181831
ACCESSION NUMBER:		0000899171-06-000033
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20060517
FILED AS OF DATE:		20060518
DATE AS OF CHANGE:		20060518

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CDW CORP
		CENTRAL INDEX KEY:			0000899171
		STANDARD INDUSTRIAL CLASSIFICATION:	RETAIL-CATALOG & MAIL-ORDER HOUSES [5961]
		IRS NUMBER:				363310735
		STATE OF INCORPORATION:			IL
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		200 N MILWAUKEE AVE
		CITY:			VERNON HILLS
		STATE:			IL
		ZIP:			60061
		BUSINESS PHONE:		8474656000

	MAIL ADDRESS:	
		STREET 1:		200 N MILWAUKEE AVE
		CITY:			VERNON HILLS
		STATE:			IL
		ZIP:			60061

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	CDW COMPUTER CENTERS INC
		DATE OF NAME CHANGE:	19930322

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			COWELL CASEY
		CENTRAL INDEX KEY:			0001158157

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-21796
		FILM NUMBER:		06853258

	BUSINESS ADDRESS:	
		STREET 1:		3000 RESEARCH DRIVE
		CITY:			RICHARDSON
		STATE:			TX
		ZIP:			75802
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2006-05-17</periodOfReport>

    <issuer>
        <issuerCik>0000899171</issuerCik>
        <issuerName>CDW CORP</issuerName>
        <issuerTradingSymbol>CDWC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001158157</rptOwnerCik>
            <rptOwnerName>COWELL CASEY</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>200 NORTH MILWAUKEE AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>VERNON HILLS</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60061</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common stock, $.01 par value</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>130166</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common stock, $.01 par value</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>7574</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>MKW Partners, L.P.</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Options (Right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>55.40</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2006-05-17</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>5462</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2007-05-17</value>
            </exerciseDate>
            <expirationDate>
                <value>2016-05-17</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock, $.01 par value</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>5462</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5462</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The reporting person disclaims beneficial ownership of these securities, except to the extent of his pecuniary interest therein.  This report shall not be deemed an admission that the reporting person is the beneficial owner of such securities, except to the extent of his pecuniary interest therein, for purposes of Section 16 or for any other purpose.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Robert J. Welyki, Attorney-in-fact</signatureName>
        <signatureDate>2006-05-18</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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