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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 JamxZo9OT6UiDcArRFML9g6QFdIgQADXVYYew4lAjAK+XMFVVH6laSlWmE5JK4jD
 HmabZkXtwAI8VjDJf5CLpg==

<SEC-DOCUMENT>0001256730-03-000001.txt : 20030729
<SEC-HEADER>0001256730-03-000001.hdr.sgml : 20030729
<ACCEPTANCE-DATETIME>20030729100522
ACCESSION NUMBER:		0001256730-03-000001
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030726
FILED AS OF DATE:		20030729

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CMGI INC
		CENTRAL INDEX KEY:			0000914712
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-DIRECT MAIL ADVERTISING SERVICES [7331]
		IRS NUMBER:				042921333
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0731

	BUSINESS ADDRESS:	
		STREET 1:		100 BRICKSTONE SQUARE
		STREET 2:		FIRST FLOOR
		CITY:			ANDOVER
		STATE:			MA
		ZIP:			01810
		BUSINESS PHONE:		9786843600

	MAIL ADDRESS:	
		STREET 1:		100 BRICKSTONE SQUARE
		CITY:			ANDOVER
		STATE:			MA
		ZIP:			01810

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	CMG INFORMATION SERVICES INC
		DATE OF NAME CHANGE:	19981007

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			KRAFT JONATHAN
		CENTRAL INDEX KEY:			0001232428

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-23262
		FILM NUMBER:		03807326

	MAIL ADDRESS:	
		STREET 1:		C/O KRAFT GROUP
		STREET 2:		ONE PATRIOT PLACE
		CITY:			FOXBORO
		STATE:			MA
		ZIP:			02035
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>

<ownershipDocument>

    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2003-07-26</periodOfReport>


    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000914712</issuerCik>
        <issuerName>CMGI INC</issuerName>
        <issuerTradingSymbol>CMGI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001232428</rptOwnerCik>
            <rptOwnerName>KRAFT JONATHAN</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O KRAFT GROUP</rptOwnerStreet1>
            <rptOwnerStreet2>ONE PATRIOT PLACE</rptOwnerStreet2>
            <rptOwnerCity>FOXBORO</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02035</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>

        <derivativeTransaction>
            <securityTitle>
                <value>Director Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>1.72</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2003-07-26</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>24000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2003-08-26</value>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2013-07-26</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>24000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>24000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>

    </derivativeTable>

    <footnotes>
        <footnote id="F1">Option vests and becomes exercisable as to 1/36th of the number of shares subject to the option on each monthly anniversary date of the date of grant provided that the optionee serves as a director on such monthly anniversary date.</footnote>
    </footnotes>


    <ownerSignature>
        <signatureName>/s/ Thomas B. Rosedale pursuant to POA</signatureName>
        <signatureDate>2003-07-29</signatureDate>
    </ownerSignature>

</ownershipDocument>

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