<SUBMISSION>
<ACCESSION-NUMBER>0001110803-05-000028
<TYPE>3
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20050408
<FILING-DATE>20050412
<DATE-OF-FILING-DATE-CHANGE>20050412
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>Kersey Alan
<CIK>0001323528
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>3
<ACT>34
<FILE-NUMBER>000-30361
<FILM-NUMBER>05747285
</FILING-VALUES>
<BUSINESS-ADDRESS>
<PHONE>858-202-4606
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>9885 TOWNE CENTRE DRIVE
<CITY>SAN DIEGO
<STATE>CA
<ZIP>92121
</MAIL-ADDRESS>
</REPORTING-OWNER>
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>ILLUMINA INC
<CIK>0001110803
<ASSIGNED-SIC>3826
<IRS-NUMBER>330804655
<STATE-OF-INCORPORATION>CA
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>9885 TOWNE CENTRE DRIVE
<STREET2>.
<CITY>SAN DIEGO
<STATE>CA
<ZIP>92121
<PHONE>8582024500
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>9885 TOWN CENTRE DRIVE
<STREET2>.
<CITY>SAN DIEGO
<STATE>CA
<ZIP>92121
</MAIL-ADDRESS>
</ISSUER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>edgardoc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2005-04-08</periodOfReport>

    <noSecuritiesOwned>1</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001110803</issuerCik>
        <issuerName>ILLUMINA INC</issuerName>
        <issuerTradingSymbol>ILMN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001323528</rptOwnerCik>
            <rptOwnerName>Kersey Alan</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>9885 TOWNE CENTRE DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SAN DIEGO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>92121</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>V.P. &amp; Site Manager</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <ownerSignature>
        <signatureName>By: Connie Brick  For: Alan D. Kersey</signatureName>
        <signatureDate>2005-04-12</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
