-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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 z5k6bkrUBhvs8chaQYXsxQ==

<SEC-DOCUMENT>0001179286-05-000001.txt : 20050207
<SEC-HEADER>0001179286-05-000001.hdr.sgml : 20050207
<ACCEPTANCE-DATETIME>20050207122033
ACCESSION NUMBER:		0001179286-05-000001
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20050203
FILED AS OF DATE:		20050207
DATE AS OF CHANGE:		20050207

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MERCURY INTERACTIVE CORP
		CENTRAL INDEX KEY:			0000867058
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-PREPACKAGED SOFTWARE [7372]
		IRS NUMBER:				770224776
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		379 N. WHISMAN ROAD
		CITY:			MOUNTAIN VIEW
		STATE:			CA
		ZIP:			94043-3969
		BUSINESS PHONE:		6506035300

	MAIL ADDRESS:	
		STREET 1:		379 N. WHISMAN ROAD
		CITY:			MOUNTAIN VIEW
		STATE:			CA
		ZIP:			94043-3969

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	MERCURY INTERACTIVE CORPORATION
		DATE OF NAME CHANGE:	19930910

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			SMITH DOUGLAS P
		CENTRAL INDEX KEY:			0001179286

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-22350
		FILM NUMBER:		05579617

	BUSINESS ADDRESS:	
		STREET 1:		C/O MERCURY INTERACTIVE CORPORATION
		STREET 2:		1325 BORREGAS AVENUE
		CITY:			SUNNYVALE
		STATE:			CA
		ZIP:			94089
		BUSINESS PHONE:		650-603-5200

	MAIL ADDRESS:	
		STREET 1:		379 N. WHISMAN ROAD
		CITY:			MOUNTAIN VIEW
		STATE:			CA
		ZIP:			94043
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2005-02-03</periodOfReport>

    <issuer>
        <issuerCik>0000867058</issuerCik>
        <issuerName>MERCURY INTERACTIVE CORP</issuerName>
        <issuerTradingSymbol>MERQ</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001179286</rptOwnerCik>
            <rptOwnerName>SMITH DOUGLAS P</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>MERCURY INTERACTIVE CORPORATION</rptOwnerStreet1>
            <rptOwnerStreet2>379 N. WHISMAN ROAD</rptOwnerStreet2>
            <rptOwnerCity>MOUNTAIN VIEW</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94043</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Executive VP &amp; CFO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3340</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Employee Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>48.94</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2005-02-03</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>30000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2006-02-03</value>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2015-02-03</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>30000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1060000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">25% of the total number of shares subject to the option vest one year from the vesting commencement date and the remaining 75% vest on a monthly basis over the next 36 months.  The option is immediately exercisable for all shares subject to the option, including those that have not yet vested, however, unvested shares purchased through option exercises are subject to the issuer's right of repurchase upon termination of employment.</footnote>
        <footnote id="F2">Includes 1,035 shares acquired pursuant to the issuer's employee stock purchase plan on February 15, 2004.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Susan J. Skaer, Attorney-in-fact for Douglas P. Smith</signatureName>
        <signatureDate>2005-02-04</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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