<SEC-DOCUMENT>0001127602-18-018874.txt : 20180524
<SEC-HEADER>0001127602-18-018874.hdr.sgml : 20180524
<ACCEPTANCE-DATETIME>20180524191853
ACCESSION NUMBER:		0001127602-18-018874
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20180522
FILED AS OF DATE:		20180524
DATE AS OF CHANGE:		20180524

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			EPSTEIN ROBERT S
		CENTRAL INDEX KEY:			0001252004

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-35406
		FILM NUMBER:		18859280

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ILLUMINA INC
		CENTRAL INDEX KEY:			0001110803
		STANDARD INDUSTRIAL CLASSIFICATION:	LABORATORY ANALYTICAL INSTRUMENTS [3826]
		IRS NUMBER:				330804655
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0101

	BUSINESS ADDRESS:	
		STREET 1:		5200 ILLUMINA WAY
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92122
		BUSINESS PHONE:		8582024500

	MAIL ADDRESS:	
		STREET 1:		5200 ILLUMINA WAY
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92122
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>form4.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2018-05-22</periodOfReport>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001252004</rptOwnerCik>
            <rptOwnerName>EPSTEIN ROBERT S</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>5200 ILLUMINA WAY</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SAN DIEGO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>92122</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2018-05-22</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>922</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>270.80</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5666</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2018-05-23</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1473</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>7139</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Grant of restricted stock units. 100% of the shares subject to the restricted stock unit award shall vest on the earlier of (i) the one year anniversary of the date of grant of the award and (ii) the date immediately preceding the date of the annual meeting of the company's stockholders for the year following the year of grant of the award, provided, in each case, that the awardee continues to serve as a director on such date.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>By: Scott M. Davies for Robert S. Epstein</signatureName>
        <signatureDate>2018-05-24</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
