<?xml version="1.0"?>

<ownershipDocument>

    <documentType>3</documentType>

    <periodOfReport>2003-06-05</periodOfReport>


    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001101239</issuerCik>
        <issuerName>EQUINIX INC</issuerName>
        <issuerTradingSymbol>EQIX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001104329</rptOwnerCik>
            <rptOwnerName>CROSSLINK CAPITAL INC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>Affiliate of Director</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>
    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001242232</rptOwnerCik>
            <rptOwnerName>CROSSLINK CROSSOVER  FUND III LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>Affiliate of Director</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>
    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001242229</rptOwnerCik>
            <rptOwnerName>CROSSOVER FUND III MANAGMENT LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>Affiliate of Director</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>
    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001242235</rptOwnerCik>
            <rptOwnerName>CROSSLINK VENTURES IV LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>Affiliate of Director</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>
    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001242237</rptOwnerCik>
            <rptOwnerName>CROSSLINK VENTURES IV HOLDINGS LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>Affiliate of Director</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>
    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001242264</rptOwnerCik>
            <rptOwnerName>CROSSLINK VERWALTUNGS GMBH</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>Affiliate of Director</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>
    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001242239</rptOwnerCik>
            <rptOwnerName>STARK MICHAEL J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>Affiliate of Director</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>
    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001242240</rptOwnerCik>
            <rptOwnerName>KAUFMAN SEYMOUR F</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>Affiliate of Director</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>
    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001242241</rptOwnerCik>
            <rptOwnerName>JACIMOVIC VLADIMIR S</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>Affiliate of Director</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>
    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001240055</rptOwnerCik>
            <rptOwnerName>HROMADKO GARY</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>Affiliate of Director</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeSecurity>
        <securityTitle>
            <value>Series A-2 Convertible Secured Noe Due 2007</value>
        </securityTitle>
        <conversionOrExercisePrice>
            <value>4</value>
        </conversionOrExercisePrice>
        <exerciseDate>
            <value>2003-06-05</value>
        </exerciseDate>
        <expirationDate>
            <value>2007-11-01</value>
        </expirationDate>
        <underlyingSecurity>
            <underlyingSecurityTitle>
                <value>Common Stock</value>
            </underlyingSecurityTitle>
            <underlyingSecurityShares>
                <value>2375000</value>
            </underlyingSecurityShares>
        </underlyingSecurity>
        <ownershipNature>
            <directOrIndirectOwnership>
                <value>I</value>
            </directOrIndirectOwnership>
            <natureOfOwnership>
                <value>See Notes</value>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
                <footnoteId id="F3"/>
                <footnoteId id="F4"/>
                <footnoteId id="F5"/>
                <footnoteId id="F6"/>
            </natureOfOwnership>
        </ownershipNature>
    </derivativeSecurity>

    <derivativeSecurity>
        <securityTitle>
            <value>Series A-2 Convertible Secured Note Due 2007</value>
        </securityTitle>
        <conversionOrExercisePrice>
            <value>4</value>
        </conversionOrExercisePrice>
        <exerciseDate>
            <value>2003-06-05</value>
        </exerciseDate>
        <expirationDate>
            <value>2007-11-01</value>
        </expirationDate>
        <underlyingSecurity>
            <underlyingSecurityTitle>
                <value>Common Stock</value>
            </underlyingSecurityTitle>
            <underlyingSecurityShares>
                <value>125000</value>
            </underlyingSecurityShares>
        </underlyingSecurity>
        <ownershipNature>
            <directOrIndirectOwnership>
                <value>D</value>
                <footnoteId id="F7"/>
            </directOrIndirectOwnership>
        </ownershipNature>
    </derivativeSecurity>

    <derivativeSecurity>
        <securityTitle>
            <value>Common Stock Warrant (right to buy)</value>
        </securityTitle>
        <conversionOrExercisePrice>
            <value>0.01</value>
        </conversionOrExercisePrice>
        <exerciseDate>
            <value>2003-06-05</value>
        </exerciseDate>
        <expirationDate>
            <value>2007-11-01</value>
        </expirationDate>
        <underlyingSecurity>
            <underlyingSecurityTitle>
                <value>Common Stock</value>
            </underlyingSecurityTitle>
            <underlyingSecurityShares>
                <value>475000</value>
            </underlyingSecurityShares>
        </underlyingSecurity>
        <ownershipNature>
            <directOrIndirectOwnership>
                <value>I</value>
            </directOrIndirectOwnership>
            <natureOfOwnership>
                <value>See Notes</value>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
                <footnoteId id="F3"/>
                <footnoteId id="F4"/>
                <footnoteId id="F5"/>
                <footnoteId id="F6"/>
            </natureOfOwnership>
        </ownershipNature>
    </derivativeSecurity>

    <derivativeSecurity>
        <securityTitle>
            <value>Common Stock Warrant (right to buy)</value>
        </securityTitle>
        <conversionOrExercisePrice>
            <value>0.01</value>
        </conversionOrExercisePrice>
        <exerciseDate>
            <value>2003-06-05</value>
        </exerciseDate>
        <expirationDate>
            <value>2007-11-01</value>
        </expirationDate>
        <underlyingSecurity>
            <underlyingSecurityTitle>
                <value>Common Stock</value>
            </underlyingSecurityTitle>
            <underlyingSecurityShares>
                <value>25000</value>
            </underlyingSecurityShares>
        </underlyingSecurity>
        <ownershipNature>
            <directOrIndirectOwnership>
                <value>D</value>
                <footnoteId id="F7"/>
            </directOrIndirectOwnership>
        </ownershipNature>
    </derivativeSecurity>

    <footnotes>
        <footnote id="F1">The reporting persons (the &quot;Reporting Persons&quot;) are Crosslink Capital, Inc. (&quot;Crosslink&quot;), Crossover Fund III Management, L.L.C. (&quot;Crossover III Management&quot;), Crosslink Ventures IV Holdings, L.L.C. (&quot;Ventures IV Holdings&quot;), Crosslink Verwaltungs GmbH (&quot;Verwaltungs&quot;), Michael J. Stark, Seymour F. Kaufman, Vladimir S. Jacimovic, Daniel John Dunn, Thomas Edward Bliska, Gary Hromadko, Crosslink Crossover Fund III, L.P. (&quot;Crossover Fund III&quot;) and Crosslink Ventures IV, L.P. (&quot;Ventures IV&quot;).  Crosslink is an investment adviser to investment funds of which Crossover III Management, Ventures IV Holdings or Verwaltungs is the general partner, manager or the holder of Class B Units, including Crossover Fund III and Ventures IV, and other investment funds.  Crossover III Management is also the investment adviser to investment funds.</footnote>
        <footnote id="F2">Mr. Stark and Mr. Kaufman are control persons of Crosslink.  Mr. Stark, Mr. Kaufman, Mr. Bliska, Mr. Dunn and Mr. Jacimovic are control persons of Crossover III Management.  Mr. Stark and Mr. Jacimovic are control persons of Ventures IV Holdings and Verwaltungs.</footnote>
        <footnote id="F3">The Reporting Persons purchased the securities reported on this Form 3 directly from Equinix, Inc. (the &quot;Issuer&quot;) in a private placement (the &quot;Private Placement&quot;).  In connection with the Private Placement, the Issuer amended its bylaws to provide that a representative of the Reporting Persons would be nominated to serve as a director of the Issuer.  Pursuant to that amendment, Mr. Hromadko became a member of the Issuer's board of directors and serves as that representative.</footnote>
        <footnote id="F4">Crosslink, Crossover III Management, Ventures IV Holdings, Verwaltungs, Mr. Stark, Mr. Kaufman, Mr. Jacimovic, Mr. Dunn, Mr. Bliska and Mr. Hromadko are filing this Form 3 jointly as a group, but disclaim membership in a group, within the meaning of Rule 13d-5(b) under the Securities Exchange Act of 1934, as amended (the &quot;Exchange Act&quot;), with any other person.  Crossover Fund III and Ventures IV are filing this Form 3 jointly with the other Reporting Persons, but not as members of a group, and they expressly disclaim membership in a group, within the meaning of Rule 13d-5(b), with any other person.</footnote>
        <footnote id="F5">These securities are held directly by investment funds to which Crosslink or Crossover III Management is investment adviser, including Crossover Fund III and Ventures IV, for the benefit of the investors in those funds.  These securities are indirectly beneficially owned by Crosslink or Crossover III Management as the investment adviser to each of those funds, by Crossover III Management, Ventures IV Holdings and Verwaltungs as the general partner, manager or holder of Class B Units of each of those funds, and by Mr. Stark, Mr. Kaufman, Mr. Jacimovic, Mr. Bliska and Mr. Dunn as the various control persons of those entities.  The Reporting Persons, except for Crossover Fund III and Ventures IV, disclaim beneficial ownership of such securities except to the extent of their respective pecuniary interest therein.</footnote>
        <footnote id="F6">The filing of this Form 3 on behalf of Crossover Fund III and Ventures IV should not be construed as an admission that either of them is, and each disclaims that it is, the beneficial owner as defined in Rule 13d-3 under the Exchange Act, of any of the Stock covered by this Form 3.  No client account of Crosslink or Crossover III Management, other than Crossover Fund III and Ventures IV, holds more than ten percent of the outstanding stock of the Issuer.</footnote>
        <footnote id="F7">These securities are beneficially owned directly by Mr. Hromadko.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Crosslink Capital, Inc. by Michael J. Stark, President</signatureName>
        <signatureDate>2003-06-12</signatureDate>
    </ownerSignature>
    <ownerSignature>
        <signatureName>Crosslink Crossover Fund III, L.P. by Michael J. Stark, Senior Fund Manager</signatureName>
        <signatureDate>2003-06-12</signatureDate>
    </ownerSignature>
    <ownerSignature>
        <signatureName>Crossover Fund III Management, L.L.C. by Michael J. Stark, Senior Fund Manager</signatureName>
        <signatureDate>2003-06-12</signatureDate>
    </ownerSignature>
    <ownerSignature>
        <signatureName>Crosslink Ventures IV, L.P. by Michael J. Stark, Senior Fund Manager</signatureName>
        <signatureDate>2003-06-12</signatureDate>
    </ownerSignature>
    <ownerSignature>
        <signatureName>Crosslink Ventures IV Holdings, L.L.C. by Michael J. Stark, Senior Fund Manager</signatureName>
        <signatureDate>2003-06-12</signatureDate>
    </ownerSignature>
    <ownerSignature>
        <signatureName>Crosllink Verwaltungs GmbH, by Michael J. Stark, Managing Director</signatureName>
        <signatureDate>2003-06-12</signatureDate>
    </ownerSignature>
    <ownerSignature>
        <signatureName>Michael J. Stark</signatureName>
        <signatureDate>2003-06-12</signatureDate>
    </ownerSignature>
    <ownerSignature>
        <signatureName>Seymour F. Kaufman</signatureName>
        <signatureDate>2003-06-12</signatureDate>
    </ownerSignature>
    <ownerSignature>
        <signatureName>Vladimir S. Jacimovic</signatureName>
        <signatureDate>2003-06-12</signatureDate>
    </ownerSignature>
    <ownerSignature>
        <signatureName>Gary Hromadko</signatureName>
        <signatureDate>2003-06-12</signatureDate>
    </ownerSignature>

</ownershipDocument>

