-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 U5w8aZ0+mRrDjUYkjD5ceMOFMyDoBJeyBtw9FYWeLVLQedbbOpZCfUq+862i0HGc
 0p1Yuu68HrA5kJK2nkp6YA==

<SEC-DOCUMENT>0001224168-03-000001.txt : 20030919
<SEC-HEADER>0001224168-03-000001.hdr.sgml : 20030919
<ACCEPTANCE-DATETIME>20030919161935
ACCESSION NUMBER:		0001224168-03-000001
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030918
FILED AS OF DATE:		20030919

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			JOHANNESSEN JAN
		CENTRAL INDEX KEY:			0001224168

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-18032
		FILM NUMBER:		03902848

	MAIL ADDRESS:	
		STREET 1:		5555 NE MOORE CT.
		CITY:			HILLSBORO
		STATE:			OR
		ZIP:			97124

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			LATTICE SEMICONDUCTOR CORP
		CENTRAL INDEX KEY:			0000855658
		STANDARD INDUSTRIAL CLASSIFICATION:	SEMICONDUCTORS & RELATED DEVICES [3674]
		IRS NUMBER:				930835214
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0101

	BUSINESS ADDRESS:	
		STREET 1:		5555 NE MOORE COURT
		CITY:			HILLSBORO
		STATE:			OR
		ZIP:			97124-6421
		BUSINESS PHONE:		5032688000

	MAIL ADDRESS:	
		STREET 1:		5555 NE MOORE COURT
		CITY:			HILLSBORO
		STATE:			OR
		ZIP:			97124
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>

<ownershipDocument>

    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2003-09-18</periodOfReport>


    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000855658</issuerCik>
        <issuerName>LATTICE SEMICONDUCTOR CORP</issuerName>
        <issuerTradingSymbol>LSCC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001224168</rptOwnerCik>
            <rptOwnerName>JOHANNESSEN JAN</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>5555 NE MOORE CT.</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>HILLSBORO</rptOwnerCity>
            <rptOwnerState>OR</rptOwnerState>
            <rptOwnerZipCode>97124</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Vice President, Investments</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>

        <derivativeTransaction>
            <securityTitle>
                <value>Employee Option to Buy</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>8.21</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2003-09-18</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>91429</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2003-12-18</value>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2013-09-18</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>91429</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>91429</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>

    </derivativeTable>

    <footnotes>
        <footnote id="F1">Grant of options to purchase common stock in connection with the reporting person's election to participate in the Lattice Semiconductor Corporation Stock Option Exchange Program pursuant to the Schedule TO originally filed by Lattice Semiconductor Corporation with the Securities and Exchange Commission on February 13, 2003.</footnote>
        <footnote id="F2">This option to purchase shares of common stock vests as follows:  12.5% of the shares vest on 12/18/2003.  12.5% vest each three months thereafter until all shares are vested on 9/18/2005.</footnote>
    </footnotes>


    <ownerSignature>
        <signatureName>Jan Johannessen</signatureName>
        <signatureDate>2003-09-18</signatureDate>
    </ownerSignature>

</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----