-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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 w8KJ7b5VGJKxPAM5TJvrUg==

<SEC-DOCUMENT>0000920148-03-000123.txt : 20030703
<SEC-HEADER>0000920148-03-000123.hdr.sgml : 20030703
<ACCEPTANCE-DATETIME>20030703124520
ACCESSION NUMBER:		0000920148-03-000123
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030701
FILED AS OF DATE:		20030703

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			MITTELSTAEDT ROBERT E JR
		CENTRAL INDEX KEY:			0001200847

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-11353
		FILM NUMBER:		03774525

	BUSINESS ADDRESS:	
		STREET 1:		C/O LAB CORP
		STREET 2:		430 S SPRING ST
		CITY:			BURLINGTON
		STATE:			NC
		ZIP:			27215
		BUSINESS PHONE:		3364365066

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			LABORATORY CORP OF AMERICA HOLDINGS
		CENTRAL INDEX KEY:			0000920148
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-MEDICAL LABORATORIES [8071]
		IRS NUMBER:				133757370
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		358 S MAIN ST
		CITY:			BURLINGTON
		STATE:			NC
		ZIP:			27215
		BUSINESS PHONE:		3362291127

	MAIL ADDRESS:	
		STREET 1:		358 S MAIN ST
		CITY:			BURLINGTON
		STATE:			NC
		ZIP:			27215

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	NATIONAL HEALTH LABORATORIES HOLDINGS INC
		DATE OF NAME CHANGE:	19940314
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>

<ownershipDocument>

    <documentType>4</documentType>

    <periodOfReport>2003-07-01</periodOfReport>


    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000920148</issuerCik>
        <issuerName>LABORATORY CORP OF AMERICA HOLDINGS</issuerName>
        <issuerTradingSymbol>LH</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001200847</rptOwnerCik>
            <rptOwnerName>MITTELSTAEDT ROBERT E JR</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeSecurity>
        <securityTitle>
            <value>Common Stock</value>
        </securityTitle>
        <transactionDate>
            <value>2003-07-01</value>
        </transactionDate>
        <transactionCoding>
            <transactionFormType>4</transactionFormType>
            <transactionCode>A</transactionCode>
            <equitySwapInvolved>0</equitySwapInvolved>
        </transactionCoding>
        <transactionTimeliness>
            <value></value>
        </transactionTimeliness>
        <transactionAmounts>
            <transactionShares>
                <value>55</value>
                <footnoteId id="F1"/>
            </transactionShares>
            <transactionValue>
                <value>29.87</value>
            </transactionValue>
            <transactionAcquiredDisposedCode>
                <value>A</value>
            </transactionAcquiredDisposedCode>
        </transactionAmounts>
        <postTransactionAmounts>
            <sharesOwnedFollowingTransaction>
                <value>9971</value>
                <footnoteId id="F2"/>
            </sharesOwnedFollowingTransaction>
        </postTransactionAmounts>
        <ownershipNature>
            <directOrIndirectOwnership>
                <value>D</value>
            </directOrIndirectOwnership>
        </ownershipNature>
    </nonDerivativeSecurity>

    <footnotes>
        <footnote id="F1">Stock award represents half the monthly Director retainer pursuant to the Laboratory Corporation of America Holdings 1995 Stock Plan for Non-Employee Directors.</footnote>
        <footnote id="F2">Amount shown reflects a 2-for-1 stock split effective on May 10, 2002.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Bradford T. Smith, Attorney-in-Fact for Robert E. Mittelstaedt</signatureName>
        <signatureDate>2003-07-02</signatureDate>
    </ownerSignature>

</ownershipDocument>

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