<SUBMISSION>
<ACCESSION-NUMBER>0000920148-03-000120
<TYPE>4
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20030602
<FILING-DATE>20030604
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>BELINGARD JEAN LUC
<CIK>0001200845
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>001-11353
<FILM-NUMBER>03731057
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>C/O APPLERA CORP
<STREET2>301 MERRITT 7
<CITY>NORWALK
<STATE>CT
<ZIP>06856-5435
<PHONE>2038402000
</BUSINESS-ADDRESS>
</REPORTING-OWNER>
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>LABORATORY CORP OF AMERICA HOLDINGS
<CIK>0000920148
<ASSIGNED-SIC>8071
<IRS-NUMBER>133757370
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>358 S MAIN ST
<CITY>BURLINGTON
<STATE>NC
<ZIP>27215
<PHONE>3362291127
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>358 S MAIN ST
<CITY>BURLINGTON
<STATE>NC
<ZIP>27215
</MAIL-ADDRESS>
<FORMER-COMPANY>
<FORMER-CONFORMED-NAME>NATIONAL HEALTH LABORATORIES HOLDINGS INC
<DATE-CHANGED>19940314
</FORMER-COMPANY>
</ISSUER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>

<ownershipDocument>

    <documentType>4</documentType>

    <periodOfReport>2003-06-02</periodOfReport>


    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001200845</rptOwnerCik>
            <rptOwnerName>BELINGARD JEAN LUC</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>2003-06-02</value>
        </transactionDate>
        <transactionCoding>
            <transactionFormType>4</transactionFormType>
            <transactionCode>A</transactionCode>
            <equitySwapInvolved>0</equitySwapInvolved>
        </transactionCoding>
        <transactionTimeliness>
            <value></value>
        </transactionTimeliness>
        <transactionAmounts>
            <transactionShares>
                <value>52</value>
            </transactionShares>
            <transactionValue>
                <value>31.47</value>
            </transactionValue>
            <transactionAcquiredDisposedCode>
                <value>A</value>
            </transactionAcquiredDisposedCode>
        </transactionAmounts>
        <postTransactionAmounts>
            <sharesOwnedFollowingTransaction>
                <value>16238</value>
                <footnoteId id="F1"/>
            </sharesOwnedFollowingTransaction>
        </postTransactionAmounts>
        <ownershipNature>
            <directOrIndirectOwnership>
                <value>D</value>
            </directOrIndirectOwnership>
        </ownershipNature>
    </nonDerivativeSecurity>

    <footnotes>
        <footnote id="F1">Amount shown reflects a 2-for-one stock split effective on May 10, 2002.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Bradford T. Smith, Attorney-In-Fact for Jean-Luc Belingard</signatureName>
        <signatureDate>2003-06-03</signatureDate>
    </ownerSignature>

</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
