<?xml version="1.0"?><?xml-stylesheet type="text/xsl" href="../4_X02.xsl"?><ownershipDocument>    <schemaVersion>X0303</schemaVersion>    <documentType>4</documentType>    <periodOfReport>2010-03-05</periodOfReport>    <issuer>        <issuerCik>0000203527</issuerCik>        <issuerName>VARIAN MEDICAL SYSTEMS INC</issuerName>        <issuerTradingSymbol>VAR</issuerTradingSymbol>    </issuer>    <reportingOwner>        <reportingOwnerId>            <rptOwnerCik>0001217439</rptOwnerCik>            <rptOwnerName>FINNEY ELISHA W</rptOwnerName>        </reportingOwnerId>        <reportingOwnerAddress>            <rptOwnerStreet1>C/O VARIAN MEDICAL SYSTEMS</rptOwnerStreet1>            <rptOwnerStreet2>3100 HANSEN WAY, , MAIL STOP E-327</rptOwnerStreet2>            <rptOwnerCity>PALO ALTO</rptOwnerCity>            <rptOwnerState>CA</rptOwnerState>            <rptOwnerZipCode>94304-1030</rptOwnerZipCode>            <rptOwnerStateDescription></rptOwnerStateDescription>        </reportingOwnerAddress>        <reportingOwnerRelationship>            <isOfficer>1</isOfficer>            <officerTitle>SVP, Finance and CFO</officerTitle>        </reportingOwnerRelationship>    </reportingOwner>    <nonDerivativeTable>        <nonDerivativeTransaction>            <securityTitle>                <value>Common Stock</value>            </securityTitle>            <transactionDate>                <value>2010-03-05</value>            </transactionDate>            <transactionCoding>                <transactionFormType>4</transactionFormType>                <transactionCode>M</transactionCode>                <equitySwapInvolved>0</equitySwapInvolved>            </transactionCoding>            <transactionTimeliness></transactionTimeliness>            <transactionAmounts>                <transactionShares>                    <value>5000</value>                </transactionShares>                <transactionPricePerShare>                    <value>24.375</value>                </transactionPricePerShare>                <transactionAcquiredDisposedCode>                    <value>A</value>                </transactionAcquiredDisposedCode>            </transactionAmounts>            <postTransactionAmounts>                <sharesOwnedFollowingTransaction>                    <value>46282</value>                </sharesOwnedFollowingTransaction>            </postTransactionAmounts>            <ownershipNature>                <directOrIndirectOwnership>                    <value>D</value>                </directOrIndirectOwnership>            </ownershipNature>        </nonDerivativeTransaction>        <nonDerivativeTransaction>            <securityTitle>                <value>Common Stock</value>            </securityTitle>            <transactionDate>                <value>2010-03-05</value>            </transactionDate>            <transactionCoding>                <transactionFormType>4</transactionFormType>                <transactionCode>S</transactionCode>                <equitySwapInvolved>0</equitySwapInvolved>                <footnoteId id="F1"/>            </transactionCoding>            <transactionTimeliness></transactionTimeliness>            <transactionAmounts>                <transactionShares>                    <value>2502</value>                </transactionShares>                <transactionPricePerShare>                    <value>51.4467</value>                    <footnoteId id="F2"/>                </transactionPricePerShare>                <transactionAcquiredDisposedCode>                    <value>D</value>                </transactionAcquiredDisposedCode>            </transactionAmounts>            <postTransactionAmounts>                <sharesOwnedFollowingTransaction>                    <value>43780</value>                </sharesOwnedFollowingTransaction>            </postTransactionAmounts>            <ownershipNature>                <directOrIndirectOwnership>                    <value>D</value>                </directOrIndirectOwnership>            </ownershipNature>        </nonDerivativeTransaction>        <nonDerivativeTransaction>            <securityTitle>                <value>Common Stock</value>            </securityTitle>            <transactionDate>                <value>2010-03-05</value>            </transactionDate>            <transactionCoding>                <transactionFormType>4</transactionFormType>                <transactionCode>S</transactionCode>                <equitySwapInvolved>0</equitySwapInvolved>                <footnoteId id="F1"/>            </transactionCoding>            <transactionTimeliness></transactionTimeliness>            <transactionAmounts>                <transactionShares>                    <value>2498</value>                </transactionShares>                <transactionPricePerShare>                    <value>51.8951</value>                    <footnoteId id="F3"/>                </transactionPricePerShare>                <transactionAcquiredDisposedCode>                    <value>D</value>                </transactionAcquiredDisposedCode>            </transactionAmounts>            <postTransactionAmounts>                <sharesOwnedFollowingTransaction>                    <value>41282</value>                </sharesOwnedFollowingTransaction>            </postTransactionAmounts>            <ownershipNature>                <directOrIndirectOwnership>                    <value>D</value>                </directOrIndirectOwnership>            </ownershipNature>        </nonDerivativeTransaction>        <nonDerivativeHolding>            <securityTitle>                <value>Common Stock</value>            </securityTitle>            <postTransactionAmounts>                <sharesOwnedFollowingTransaction>                    <value>31371</value>                </sharesOwnedFollowingTransaction>            </postTransactionAmounts>            <ownershipNature>                <directOrIndirectOwnership>                    <value>I</value>                </directOrIndirectOwnership>                <natureOfOwnership>                    <value>By Trust</value>                </natureOfOwnership>            </ownershipNature>        </nonDerivativeHolding>    </nonDerivativeTable>    <derivativeTable>        <derivativeTransaction>            <securityTitle>                <value>Non-qualified Stock Option (Right to Buy)</value>            </securityTitle>            <conversionOrExercisePrice>                <value>24.375</value>            </conversionOrExercisePrice>            <transactionDate>                <value>2010-03-05</value>            </transactionDate>            <transactionCoding>                <transactionFormType>4</transactionFormType>                <transactionCode>M</transactionCode>                <equitySwapInvolved>0</equitySwapInvolved>            </transactionCoding>            <transactionTimeliness></transactionTimeliness>            <transactionAmounts>                <transactionShares>                    <value>5000</value>                </transactionShares>                <transactionPricePerShare>                    <value>0</value>                </transactionPricePerShare>                <transactionAcquiredDisposedCode>                    <value>D</value>                </transactionAcquiredDisposedCode>            </transactionAmounts>            <exerciseDate>                <footnoteId id="F4"/>            </exerciseDate>            <expirationDate>                <value>2012-11-14</value>            </expirationDate>            <underlyingSecurity>                <underlyingSecurityTitle>                    <value>Common Stock</value>                </underlyingSecurityTitle>                <underlyingSecurityShares>                    <value>5000</value>                </underlyingSecurityShares>            </underlyingSecurity>            <postTransactionAmounts>                <sharesOwnedFollowingTransaction>                    <value>48000</value>                </sharesOwnedFollowingTransaction>            </postTransactionAmounts>            <ownershipNature>                <directOrIndirectOwnership>                    <value>D</value>                </directOrIndirectOwnership>            </ownershipNature>        </derivativeTransaction>    </derivativeTable>    <footnotes>        <footnote id="F1">This transaction is pursuant to the filer's SEC Rule10b5-1 Stock Plan</footnote>        <footnote id="F2">The 2,502 shares were sold in multiple transactions executed on the same day at prices ranging from $50.70 to $51.69.  The detailed breakdown of executed sales will be furnished upon request.</footnote>        <footnote id="F3">The 2,498 shares were sold in multiple transactions executed on the same day at prices ranging from $51.803 to $52.140.  The detailed breakdown of executed sales will be furnished upon request.</footnote>        <footnote id="F4">Stock option granted under the Varian Medical Systems, Inc. 1990 Omnibus Stock Plan, which complies with new Rule 16b-3.  The option vests as follows: one third on 11/14/03, and the remaining shares in 24 equal installments over the 24 months following the first vesting date.</footnote>    </footnotes>    <ownerSignature>        <signatureName>/s/ John A. Thorson, Attorney in Fact for Elisha W. Finney</signatureName>        <signatureDate>2010-03-08</signatureDate>    </ownerSignature></ownershipDocument>