-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 I+PP8bao1QN/nBt+dqEAeu+O8HfTsbMt4RljHuFzRaWbNrSp67Bp3WWbwutZhYoy
 7/Yig9AE/AjS+iS3bA7vzg==

<SEC-DOCUMENT>0001209191-05-014768.txt : 20050310
<SEC-HEADER>0001209191-05-014768.hdr.sgml : 20050310
<ACCEPTANCE-DATETIME>20050310103925
ACCESSION NUMBER:		0001209191-05-014768
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20050308
FILED AS OF DATE:		20050310
DATE AS OF CHANGE:		20050310

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			LUNDEMOSE ANKER MD, PH.D, DSC
		CENTRAL INDEX KEY:			0001314821

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-15190
		FILM NUMBER:		05671030

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		631-962-2000

	MAIL ADDRESS:	
		STREET 1:		C/O OSI PHARMACEUTICALS, INC.
		STREET 2:		58 SOUTH SERVICE ROAD, SUITE 110
		CITY:			MELVILLE
		STATE:			NY
		ZIP:			11747

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			OSI PHARMACEUTICALS INC
		CENTRAL INDEX KEY:			0000729922
		STANDARD INDUSTRIAL CLASSIFICATION:	IN VITRO & IN VIVO DIAGNOSTIC SUBSTANCES [2835]
		IRS NUMBER:				133159796
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1204

	BUSINESS ADDRESS:	
		STREET 1:		58 SOUTH SERVICE RD.
		STREET 2:		SUITE 110
		CITY:			MELVILLE
		STATE:			NY
		ZIP:			11747
		BUSINESS PHONE:		631-962-2000

	MAIL ADDRESS:	
		STREET 1:		58 SOUTH SERVICE RD.
		STREET 2:		SUITE 110
		CITY:			MELVILLE
		STATE:			NY
		ZIP:			11747

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	ONCOGENE SCIENCE INC
		DATE OF NAME CHANGE:	19920703
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc4.xml
<DESCRIPTION>FORM 4 SUBMISSION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2005-03-08</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000729922</issuerCik>
        <issuerName>OSI PHARMACEUTICALS INC</issuerName>
        <issuerTradingSymbol>OSIP</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001314821</rptOwnerCik>
            <rptOwnerName>LUNDEMOSE ANKER MD, PH.D, DSC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O OSI PHARMACEUTICALS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>58 SOUTH SERVICE ROAD, SUITE 110</rptOwnerStreet2>
            <rptOwnerCity>MELVILLE</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>11747</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>See remarks</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>48.30</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2005-03-08</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>40000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2006-03-08</value>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2015-03-07</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>40000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>40000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F3"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">One third of the stock option will become exercisable one year after the date of the grant and the remainder will vest ratably on a monthly basis over the succeeding 24 months.</footnote>
        <footnote id="F2">The stock option was granted pursuant to one of the Issuer's incentive and non-qualified stock option plans and is exempt under Rule 16b-3.</footnote>
        <footnote id="F3">Includes only options with the same termination date.</footnote>
    </footnotes>

    <remarks>Dr. Lundemose is Chief Executive Officer of Prosidion Ltd., a majority-owned subsidiary of OSI Pharmaceuticals, Inc.</remarks>

    <ownerSignature>
        <signatureName>Robert L. Van Nostrand by Power of Attorney</signatureName>
        <signatureDate>2005-03-10</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----