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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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 OY3hl/QlmNbOn9Vlhd5mfA==

<SEC-DOCUMENT>0001018099-03-000087.txt : 20031003
<SEC-HEADER>0001018099-03-000087.hdr.sgml : 20031003
<ACCEPTANCE-DATETIME>20031003134309
ACCESSION NUMBER:		0001018099-03-000087
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20031001
FILED AS OF DATE:		20031003

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MILLENNIUM CHEMICALS INC
		CENTRAL INDEX KEY:			0001018099
		STANDARD INDUSTRIAL CLASSIFICATION:	INDUSTRIAL INORGANIC CHEMICALS [2810]
		IRS NUMBER:				223436215
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		230 HALF MILE ROAD
		STREET 2:		-
		CITY:			RED BANK
		STATE:			NJ
		ZIP:			07701
		BUSINESS PHONE:		7329335000

	MAIL ADDRESS:	
		STREET 1:		230 HALF MILE ROAD
		STREET 2:		-
		CITY:			RED BANK
		STATE:			NJ
		ZIP:			07701

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			CLARK WORLEY H JR
		CENTRAL INDEX KEY:			0001014814

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-12091
		FILM NUMBER:		03927327

	BUSINESS ADDRESS:	
		STREET 1:		W. H. CLARK & ASSOCIATES
		STREET 2:		20 SOUTH CLARK STREET, SUITE 2222
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60603-4203
		BUSINESS PHONE:		3125807832

	MAIL ADDRESS:	
		STREET 1:		W. H. CLARK & ASSOCIATES
		STREET 2:		20 SOUTH CLARK STREET, SUITE 2222
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60603-4203
</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>2003-10-01</periodOfReport>


    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001018099</issuerCik>
        <issuerName>MILLENNIUM CHEMICALS INC</issuerName>
        <issuerTradingSymbol>MCH</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001014814</rptOwnerCik>
            <rptOwnerName>CLARK WORLEY H JR</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>W. H. CLARK &amp; ASSOCIATES</rptOwnerStreet1>
            <rptOwnerStreet2>20 SOUTH CLARK STREET, SUITE 2222</rptOwnerStreet2>
            <rptOwnerCity>CHICAGO</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60603-4203</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>

        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock $0.01 par value/share</value>
            </securityTitle>
            <transactionDate>
                <value>2003-10-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>4484</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>9.55</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>13312</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>

    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Represents the total number of shares directly owned by the Reporting Person of which 2,094 shares were issued on October 1, 2003 under the Company's Long Term Stock Incentive Plan in partial payment of annual Director's fee and 2,390 shares were issued under the Company's Omnibus Incentive Plan in partial payment of annual Chairman of the Board fee.</footnote>
    </footnotes>


    <ownerSignature>
        <signatureName>Worley H. Clark, Jr.</signatureName>
        <signatureDate>2003-10-03</signatureDate>
    </ownerSignature>

</ownershipDocument>

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