-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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<SEC-DOCUMENT>0000904454-09-000368.txt : 20090903
<SEC-HEADER>0000904454-09-000368.hdr.sgml : 20090903
<ACCEPTANCE-DATETIME>20090903185541
ACCESSION NUMBER:		0000904454-09-000368
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20090901
FILED AS OF DATE:		20090903
DATE AS OF CHANGE:		20090903

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			SILVER LAKE PARTNERS LP
		CENTRAL INDEX KEY:			0001088186
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-14443
		FILM NUMBER:		091054598

	BUSINESS ADDRESS:	
		STREET 1:		2725 SAND HILL RD
		STREET 2:		STE 150
		CITY:			MENLO PARK
		STATE:			CA
		ZIP:			94025

	MAIL ADDRESS:	
		STREET 1:		2725 SAND HILL ROAD STE 150
		CITY:			MENLO PARK
		STATE:			CA
		ZIP:			94025

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			SILVER LAKE TECHNOLOGY INVESTORS LLC
		CENTRAL INDEX KEY:			0001269867
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-14443
		FILM NUMBER:		091054597

	BUSINESS ADDRESS:	
		STREET 1:		2725 SAND HILL RD
		STREET 2:		STE 150
		CITY:			MENLO PARK
		STATE:			CA
		ZIP:			94025
		BUSINESS PHONE:		6502338120

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			SILVER LAKE INVESTORS LP
		CENTRAL INDEX KEY:			0001099154

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-14443
		FILM NUMBER:		091054596

	BUSINESS ADDRESS:	
		STREET 1:		2725 SAND HILL RD
		STREET 2:		STE 150
		CITY:			MENLO PARK
		STATE:			CA
		ZIP:			94025
		BUSINESS PHONE:		6502338120

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Bingle Michael J
		CENTRAL INDEX KEY:			0001306831

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-14443
		FILM NUMBER:		091054595

	MAIL ADDRESS:	
		STREET 1:		SILVER LAKE TECHNOLOGY MANAGEMENT
		STREET 2:		2725 SAND HILL ROAD, SUITE 150
		CITY:			MENLO PARK
		STATE:			CA
		ZIP:			94025

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			GARTNER INC
		CENTRAL INDEX KEY:			0000749251
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-MANAGEMENT SERVICES [8741]
		IRS NUMBER:				043099750
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		56 TOP GALLANT RD
		STREET 2:		P O BOX 10212
		CITY:			STAMFORD
		STATE:			CT
		ZIP:			06904-2212
		BUSINESS PHONE:		2039640096

	MAIL ADDRESS:	
		STREET 1:		56 TOP GALLANT RD
		STREET 2:		P O BOX 10212
		CITY:			STAMFORD
		STATE:			CT
		ZIP:			06904-2212

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	GARTNER GROUP INC
		DATE OF NAME CHANGE:	19930823

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			JOYCE JOHN R
		CENTRAL INDEX KEY:			0001180451

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-14443
		FILM NUMBER:		091054594

	MAIL ADDRESS:	
		STREET 1:		SILVER LAKE PARTNERS LP
		STREET 2:		2775 SAND HILL ROAD, SUITE 100
		CITY:			MENLO PARK
		STATE:			CA
		ZIP:			94025
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2009-09-01</periodOfReport>

    <issuer>
        <issuerCik>0000749251</issuerCik>
        <issuerName>GARTNER INC</issuerName>
        <issuerTradingSymbol>IT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001088186</rptOwnerCik>
            <rptOwnerName>SILVER LAKE PARTNERS LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>2775 SAND HILL ROAD</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 100</rptOwnerStreet2>
            <rptOwnerCity>MENLO PARK</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94025</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001269867</rptOwnerCik>
            <rptOwnerName>SILVER LAKE TECHNOLOGY INVESTORS LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>2775 SAND HILL ROAD</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 100</rptOwnerStreet2>
            <rptOwnerCity>MENLO PARK</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94025</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001099154</rptOwnerCik>
            <rptOwnerName>SILVER LAKE INVESTORS LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>2775 SAND HILL ROAD</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 100</rptOwnerStreet2>
            <rptOwnerCity>MENLO PARK</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94025</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001306831</rptOwnerCik>
            <rptOwnerName>Bingle Michael J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O SILVER LAKE PARTNERS, L.P.</rptOwnerStreet1>
            <rptOwnerStreet2>2775 SAND HILL ROAD, SUITE 100</rptOwnerStreet2>
            <rptOwnerCity>MENLO PARK</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94025</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001180451</rptOwnerCik>
            <rptOwnerName>JOYCE JOHN R</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O SILVER LAKE PARTNERS, L.P.</rptOwnerStreet1>
            <rptOwnerStreet2>2775 SAND HILL ROAD, SUITE 100</rptOwnerStreet2>
            <rptOwnerCity>MENLO PARK</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94025</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $0.0005</value>
            </securityTitle>
            <transactionDate>
                <value>2009-09-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F2"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>28800</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>16.84</value>
                    <footnoteId id="F3"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>10000608</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $0.0005</value>
            </securityTitle>
            <transactionDate>
                <value>2009-09-02</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F4"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>87233</value>
                    <footnoteId id="F4"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>16.75</value>
                    <footnoteId id="F5"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>9913375</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $0.0005</value>
            </securityTitle>
            <transactionDate>
                <value>2009-09-03</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F6"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>100000</value>
                    <footnoteId id="F6"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>16.41</value>
                    <footnoteId id="F7"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>9813375</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Owned by Silver Lake Partners, L.P., Silver Lake Investors, L.P., and Silver Lake Technology Investors, L.L.C. (collectively, the &quot;Silver Lake Entities&quot;).  Silver Lake Technology Associates, L.L.C. is the General Partner of each of Silver Lake Partners, L.P. and Silver Lake Investors, L.P.  Silver Lake Partners Management Company, L.L.C. is the Manager of Silver Lake Technology Investors, L.L.C.  Each of Mr. Bingle and Mr. Joyce, who are both directors of the Issuer, is a Managing Director of each of Silver Lake Technology Associates, L.L.C. and Silver Lake Technology Management, L.L.C, the managing member of Silver Lake Partners Management Company, L.L.C.  As such, each of Mr. Bingle and Mr. Joyce could be deemed to have a shared voting and/or dispositive power over these shares.  However, each of Mr. Bingle and Mr. Joyce disclaims beneficial ownership of these shares, except to the extent of his pecuniary interest therein.</footnote>
        <footnote id="F2">Of the 28,800 shares sold by the Silver Lake Entities on September 1, 2009, (i) Silver Lake Partners, L.P. sold 26,522 shares; (ii) Silver Lake Investors, L.P. sold 762 shares; and Silver Lake Technology Investors, L.L.C. sold 1,516 shares.</footnote>
        <footnote id="F3">The price reported in Column 4 is a weighted average price.  These shares were sold in multiple transactions at prices ranging from $16.75 to $16.91.  The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.</footnote>
        <footnote id="F4">Of the 87,233 shares sold by the Silver Lake Entities on September 2, 2009, (i) Silver Lake Partners, L.P. sold 80,333 shares; (ii) Silver Lake Investors, L.P. sold 2,308 shares; and Silver Lake Technology Investors, L.L.C. sold 4,592 shares.</footnote>
        <footnote id="F5">The price reported in Column 4 is a weighted average price.  These shares were sold in multiple transactions at prices ranging from $16.70 to $16.82.  The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.</footnote>
        <footnote id="F6">Of the 100,000 shares sold by the Silver Lake Entities on September 3, 2009, (i) Silver Lake Partners, L.P. sold 92,090 shares; (ii) Silver Lake Investors, L.P. sold 2,646 shares; and Silver Lake Technology Investors, L.L.C. sold 5,264 shares.</footnote>
        <footnote id="F7">The price reported in Column 4 is a weighted average price.  These shares were sold in multiple transactions at prices ranging from $16.40 to $16.62.  The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Karen M. King, Senior Vice President and General Counsel of Silver Lake Technology Associates, L.L.C., General Partner of Silver Lake Partners, L.P.</signatureName>
        <signatureDate>2009-09-03</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Karen M. King, Senior Vice President and General Counsel of Silver Lake Technology Associates, L.L.C., General Partner of Silver Lake Investors, L.P.</signatureName>
        <signatureDate>2009-09-03</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Karen M. King, Sr. VP &amp; GC of Silver Lake Technology Management, LLC, managing member of Silver Lake Partners Management Company, LLC, Manager of Silver Lake Technology Investors, LLC</signatureName>
        <signatureDate>2009-09-03</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Karen M. King, Attorney-in-Fact for Michael J. Bingle</signatureName>
        <signatureDate>2009-09-03</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Karen M. King, Attorney-in-Fact for John R. Joyce</signatureName>
        <signatureDate>2009-09-03</signatureDate>
    </ownerSignature>
</ownershipDocument>
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</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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