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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>0001199242-03-000042.txt : 20030725
<SEC-HEADER>0001199242-03-000042.hdr.sgml : 20030725
<ACCEPTANCE-DATETIME>20030725120523
ACCESSION NUMBER:		0001199242-03-000042
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030724
FILED AS OF DATE:		20030725

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			LOVE RICHARD L
		CENTRAL INDEX KEY:			0001201041

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-21244
		FILM NUMBER:		03802613

	BUSINESS ADDRESS:	
		STREET 1:		ILEX ONCOLOGY INC
		STREET 2:		4545 HORIZON HILL BLVD.
		CITY:			SAN ANTONIO
		STATE:			TX
		ZIP:			78229-2263

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			PAREXEL INTERNATIONAL CORP
		CENTRAL INDEX KEY:			0000799729
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-COMMERCIAL PHYSICAL & BIOLOGICAL RESEARCH [8731]
		IRS NUMBER:				042776269
		STATE OF INCORPORATION:			MA
		FISCAL YEAR END:			0630

	BUSINESS ADDRESS:	
		STREET 1:		195 WEST ST
		CITY:			WALTHAM
		STATE:			MA
		ZIP:			02451
		BUSINESS PHONE:		7814879900

	MAIL ADDRESS:	
		STREET 1:		195 WEST ST
		CITY:			WALTHAM
		STATE:			MA
		ZIP:			02451
</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>2003-07-24</periodOfReport>


    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000799729</issuerCik>
        <issuerName>PAREXEL INTERNATIONAL CORP</issuerName>
        <issuerTradingSymbol>PRXL</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001201041</rptOwnerCik>
            <rptOwnerName>LOVE RICHARD L</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>

    <derivativeSecurity>
        <securityTitle>
            <value>Option, with right to buy</value>
        </securityTitle>
        <conversionOrExercisePrice>
            <value>13.88</value>
        </conversionOrExercisePrice>
        <transactionDate>
            <value>2003-07-24</value>
        </transactionDate>
        <transactionCoding>
            <transactionFormType>4</transactionFormType>
            <transactionCode>A</transactionCode>
            <equitySwapInvolved>0</equitySwapInvolved>
        </transactionCoding>
        <transactionTimeliness>
            <value></value>
        </transactionTimeliness>
        <transactionAmounts>
            <transactionShares>
                <value>2000</value>
            </transactionShares>
            <transactionValue>
                <value>0</value>
            </transactionValue>
            <transactionAcquiredDisposedCode>
                <value>A</value>
            </transactionAcquiredDisposedCode>
        </transactionAmounts>
        <exerciseDate>
            <value>2004-07-24</value>
            <footnoteId id="F1"/>
        </exerciseDate>
        <expirationDate>
            <value>2011-07-24</value>
        </expirationDate>
        <underlyingSecurity>
            <underlyingSecurityTitle>
                <value>Common Stock</value>
            </underlyingSecurityTitle>
            <underlyingSecurityShares>
                <value>2000</value>
            </underlyingSecurityShares>
        </underlyingSecurity>
        <postTransactionAmounts>
            <sharesOwnedFollowingTransaction>
                <value>2000</value>
            </sharesOwnedFollowingTransaction>
        </postTransactionAmounts>
        <ownershipNature>
            <directOrIndirectOwnership>
                <value>D</value>
            </directOrIndirectOwnership>
        </ownershipNature>
    </derivativeSecurity>

    <footnotes>
        <footnote id="F1">Table II, Item 6 - Options become exercisable for 33-1/3% of the total shares in annual increments commencing on the first anniversary of the date of grant.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Richard L. Love</signatureName>
        <signatureDate>2003-07-24</signatureDate>
    </ownerSignature>

</ownershipDocument>

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