<SUBMISSION>
<ACCESSION-NUMBER>0001261416-05-000025
<TYPE>4
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20051201
<FILING-DATE>20051205
<DATE-OF-FILING-DATE-CHANGE>20051205
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>HITZ DAVID
<CIK>0001007719
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>000-27130
<FILM-NUMBER>051245222
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>495 E. JAVA DRIVE
<CITY>SUNNYVALE
<STATE>CA
<ZIP>94089
</BUSINESS-ADDRESS>
</REPORTING-OWNER>
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>NETWORK APPLIANCE INC
<CIK>0001002047
<ASSIGNED-SIC>3572
<IRS-NUMBER>770307520
<STATE-OF-INCORPORATION>CA
<FISCAL-YEAR-END>0430
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>495 EAST JAVA DR
<CITY>SUNNYVALE
<STATE>CA
<ZIP>94089
<PHONE>4088226000
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>495 EAST JAVA DR
<CITY>SUNNYVALE
<STATE>CA
<ZIP>94089
</MAIL-ADDRESS>
</ISSUER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgardoc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2005-12-01</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001002047</issuerCik>
        <issuerName>NETWORK APPLIANCE INC</issuerName>
        <issuerTradingSymbol>NTAP</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001007719</rptOwnerCik>
            <rptOwnerName>HITZ DAVID</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>495 EAST JAVA DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SUNNYVALE</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94089</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Executive Vice President</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2005-12-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>25000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>29.4003</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4662250</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>by Trust2</value>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>26273</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>200</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>by Trust</value>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The sale(s) reported in this Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on April 1, 2005.</footnote>
        <footnote id="F2">The sale prices for the reported transactions were in a range of $29.07 to $29.685 per share.</footnote>
        <footnote id="F3">Shares held in trust by David Hitz, Trustee to the Sundance Trust UTA 1/17/02.  The reporting person continues to report beneficial ownership of all the issuers common stock held by the trust but disclaims beneficial ownership except to the extent of his pecuniary interest therein.</footnote>
        <footnote id="F4">Shares held in trust by The XYZZY 2000 Charitable Remainder Trust, David Hitz, Trustee.  The reporting person continues to report beneficial ownership of all the issuers common stock held by the trust but disclaims beneficial ownership except to the extent of his pecuniary interest therein.</footnote>
    </footnotes>

    <remarks>Amount of Non-Derivative Securities Beneficially Owned by Direct Ownership includes 318 shares acquired under Network Appliance, Inc. Employee Stock Purchase Plan on November 30, 2005.</remarks>

    <ownerSignature>
        <signatureName>By: Janice Mahoney by Power of Attorney  For: David Hitz</signatureName>
        <signatureDate>2005-12-01</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
