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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 Kk1E2IwP8xupYuOjt1H2EE1uUbSutGd+TXNZ6LAmIuLvzwNKuQoUywoGyx/1fVNr
 9JPTWDW211v68LP/InBGmw==

<SEC-DOCUMENT>0001181431-05-046391.txt : 20050812
<SEC-HEADER>0001181431-05-046391.hdr.sgml : 20050812
<ACCEPTANCE-DATETIME>20050812113558
ACCESSION NUMBER:		0001181431-05-046391
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20050811
FILED AS OF DATE:		20050812
DATE AS OF CHANGE:		20050812

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			PHARSIGHT CORP
		CENTRAL INDEX KEY:			0001040853
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-PREPACKAGED SOFTWARE [7372]
		IRS NUMBER:				770401273
		STATE OF INCORPORATION:			CA
		FISCAL YEAR END:			0331

	BUSINESS ADDRESS:	
		STREET 1:		800 WEST EL CAMINO REAL
		STREET 2:		STE 200
		CITY:			PALO ALTO
		STATE:			CA
		ZIP:			94040
		BUSINESS PHONE:		6503143800

	MAIL ADDRESS:	
		STREET 1:		800 WEST EL CAMINO REAL
		STREET 2:		STE 200
		CITY:			MOUNTAIN VIEW
		STATE:			CA
		ZIP:			94040

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			CHESS ROBERT
		CENTRAL INDEX KEY:			0001227886

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-31253
		FILM NUMBER:		051019782

	BUSINESS ADDRESS:	
		STREET 1:		C/O PHARSIGHT
		STREET 2:		8OO WEST EL CAMINO REAL STE 200
		CITY:			MOUNTAIN VIEW
		STATE:			CA
		ZIP:			94040
		BUSINESS PHONE:		6503143817
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>rrd89155.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2005-08-11</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001040853</issuerCik>
        <issuerName>PHARSIGHT CORP</issuerName>
        <issuerTradingSymbol>PHST</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001227886</rptOwnerCik>
            <rptOwnerName>CHESS ROBERT</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>800 WEST EL CAMINO REAL, SUITE 200</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>MOUNTAIN VIEW</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94040</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Non-Statutory Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>2.00</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2005-08-11</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>10000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2006-08-11</value>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2015-08-11</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>10000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>10000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">100% of the shares subject to the option will vest and become exercisable on August 11, 2006, provided however, that the Reporting Person continues to provide service to the Issuer through such date.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Lisa Hodges, Attorney-in-fact for Robert Chess</signatureName>
        <signatureDate>2005-08-12</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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