<?xml version="1.0"?><ownershipDocument><schemaVersion>X0101</schemaVersion>    <documentType>4</documentType><periodOfReport>2003-06-25</periodOfReport><issuer><issuerCik>0000729922</issuerCik><issuerName>OSI PHARMACEUTICALS INC</issuerName>        <issuerTradingSymbol>OSIP</issuerTradingSymbol></issuer><reportingOwner><reportingOwnerId><rptOwnerCik>0001225199</rptOwnerCik><rptOwnerName>GODDARD COLIN</rptOwnerName></reportingOwnerId><reportingOwnerAddress><rptOwnerStreet1>  </rptOwnerStreet1><rptOwnerStreet2>  </rptOwnerStreet2><rptOwnerCity>  </rptOwnerCity><rptOwnerState>  </rptOwnerState><rptOwnerZipCode>  </rptOwnerZipCode></reportingOwnerAddress><reportingOwnerRelationship><isDirector>1</isDirector><isOfficer>1</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther><officerTitle>Chief Executive Officer</officerTitle><otherText></otherText></reportingOwnerRelationship></reportingOwner><derivativeSecurity><securityTitle><value>Stock Option (Right to Buy)</value></securityTitle><conversionOrExercisePrice><value>30.74</value></conversionOrExercisePrice><transactionDate><value>2003-06-25</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>A</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionTimeliness><value></value></transactionTimeliness><transactionAmounts><transactionShares><value>60700</value></transactionShares><transactionValue><value>0</value><footnoteId id="F2" /></transactionValue><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><exerciseDate><value>2004-06-25</value><footnoteId id="F1" /></exerciseDate><expirationDate><value>2013-06-24</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>60700</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>60700</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value><footnoteId id="F3" /></directOrIndirectOwnership></ownershipNature></derivativeSecurity><footnotes><footnote id="F1">One third of the stock option becomes exercisable on 6/25/2004 and the remainder vests ratably on a monthly basis over the succeeding 24 months.</footnote><footnote id="F2">The stock option is granted pursuant to the Issuer's 2001 Incentive and Non-Qualified Stock Option Plan and is exempt under Rule 16b-3.</footnote><footnote id="F3">Includes only options with the same termination date.</footnote></footnotes><ownerSignature><signatureName>Robert L. Van Nostrand by Power of Attorney</signatureName><signatureDate>2003-06-27</signatureDate></ownerSignature></ownershipDocument>

