-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 FAGDqfWC+xIiAJ1ZLjRQQIWVpkaakdhCxpl5WUj4hYxbgWlSiM/ij/MjFv92Hu1S
 Nh3ymHdXgkPS2Pc1yIMlsg==

<SEC-DOCUMENT>0001181431-03-014034.txt : 20030715
<SEC-HEADER>0001181431-03-014034.hdr.sgml : 20030715
<ACCEPTANCE-DATETIME>20030715130633
ACCESSION NUMBER:		0001181431-03-014034
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030714
FILED AS OF DATE:		20030715

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			NATIONAL INSTRUMENTS CORP /DE/
		CENTRAL INDEX KEY:			0000935494
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-PREPACKAGED SOFTWARE [7372]
		IRS NUMBER:				741871327
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		11500 NORTH MOPAC EXPRESSWAY
		CITY:			AUSTIN
		STATE:			TX
		ZIP:			78759
		BUSINESS PHONE:		5123389119

	MAIL ADDRESS:	
		STREET 1:		11500 NORTH MOPAC EXPRESSWAY
		CITY:			AUSTIN
		STATE:			TX
		ZIP:			78759

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			TRUCHARD JAMES J
		CENTRAL INDEX KEY:			0001008359

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-25426
		FILM NUMBER:		03786782

	BUSINESS ADDRESS:	
		STREET 1:		6504 BRIDGE POINT PARKWAY
		STREET 2:		C/O NATIONAL INSTRUMENTS CORP
		CITY:			AUSTIN
		STATE:			TX
		ZIP:			78730-5039
		BUSINESS PHONE:		5127945713

	MAIL ADDRESS:	
		STREET 1:		C/O NATIONAL INSTRUMENTS CORP
		STREET 2:		6504 BRIDGE POINT PARKWAY
		CITY:			AUSTIN
		STATE:			TX
		ZIP:			78730-5039
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>rrd13226.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>
    <schemaVersion>X0101</schemaVersion>

    <documentType>4</documentType>
<periodOfReport>2003-07-14</periodOfReport>
<notSubjectToSection16>0</notSubjectToSection16>
    <issuer>
        <issuerCik>0000935494</issuerCik>
        <issuerName>NATIONAL INSTRUMENTS CORP /DE/</issuerName>
        <issuerTradingSymbol>NATI</issuerTradingSymbol></issuer>
<reportingOwner>
<reportingOwnerId>
            <rptOwnerCik>0001008359</rptOwnerCik>
            <rptOwnerName>TRUCHARD JAMES J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>1</isDirector>
<isOfficer>1</isOfficer>
<isTenPercentOwner>1</isTenPercentOwner>
<isOther>0</isOther>
<officerTitle>President and CEO</officerTitle>
<otherText></otherText></reportingOwnerRelationship></reportingOwner>
<nonDerivativeSecurity>
<securityTitle>
<value>Common Stock</value></securityTitle>
<transactionDate>
<value>2003-07-14</value></transactionDate>
<transactionCoding>
<transactionFormType>4</transactionFormType>
<transactionCode>S</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved></transactionCoding>
<transactionTimeliness>
<value></value></transactionTimeliness>
<transactionAmounts>
<transactionShares>
<value>3500</value>
<footnoteId id="F1"/></transactionShares>
<transactionValue>
<value>40.2134</value></transactionValue>
<transactionAcquiredDisposedCode>
<value>D</value></transactionAcquiredDisposedCode></transactionAmounts>
<postTransactionAmounts>
<sharesOwnedFollowingTransaction>
<value>11439861</value></sharesOwnedFollowingTransaction></postTransactionAmounts>
<ownershipNature>
<directOrIndirectOwnership>
<value>D</value></directOrIndirectOwnership>
<natureOfOwnership>
<value></value></natureOfOwnership></ownershipNature></nonDerivativeSecurity>
<footnotes>
<footnote id="F1">Shares were sold under Reporting Person&apos;s 10(b)5-1 Plan</footnote></footnotes>
<ownerSignature>
<signatureName>David G. Hugley, as attorney-in-fact for James J. Truchard</signatureName>
<signatureDate>2003-07-15</signatureDate></ownerSignature></ownershipDocument>


</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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