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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
 J7bbgV1gZjKTtw8lptCi6Oz/6G78l5dsQROoaeof5nLKlUoNcki7cCAOyugkjH1C
 zgW6oBQZZAWnm+uu4rgb4w==

<SEC-DOCUMENT>0001181431-10-050364.txt : 20101008
<SEC-HEADER>0001181431-10-050364.hdr.sgml : 20101008
<ACCEPTANCE-DATETIME>20101008165923
ACCESSION NUMBER:		0001181431-10-050364
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20101007
FILED AS OF DATE:		20101008
DATE AS OF CHANGE:		20101008

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			HADLEY PHILIP A
		CENTRAL INDEX KEY:			0001166908

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-11869
		FILM NUMBER:		101116566

	MAIL ADDRESS:	
		STREET 1:		FACTSET RESEARCH SYSTEMS
		STREET 2:		ONE GREENWICH PLAZA
		CITY:			GREENWICH
		STATE:			CT
		ZIP:			06830

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			FACTSET RESEARCH SYSTEMS INC
		CENTRAL INDEX KEY:			0001013237
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-COMPUTER PROGRAMMING, DATA PROCESSING, ETC. [7370]
		IRS NUMBER:				133362547
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0831

	BUSINESS ADDRESS:	
		STREET 1:		601 MERRITT 7
		CITY:			NORWALK
		STATE:			CT
		ZIP:			06851
		BUSINESS PHONE:		2038101000

	MAIL ADDRESS:	
		STREET 1:		601 MERRITT 7
		CITY:			NORWALK
		STATE:			CT
		ZIP:			06851
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>rrd288246.xml
<DESCRIPTION>P. HADLEY - FORM 4 - OCT 2010
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-10-07</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001013237</issuerCik>
        <issuerName>FACTSET RESEARCH SYSTEMS INC</issuerName>
        <issuerTradingSymbol>FDS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001166908</rptOwnerCik>
            <rptOwnerName>HADLEY PHILIP A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>601 MERRITT 7</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NORWALK</rptOwnerCity>
            <rptOwnerState>CT</rptOwnerState>
            <rptOwnerZipCode></rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>CEO &amp; Chairman</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>FactSet Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-10-07</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>130000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>82.33</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>903184</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <ownerSignature>
        <signatureName>Philip A. Hadley</signatureName>
        <signatureDate>2010-10-08</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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