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Proc-Type: 2001,MIC-CLEAR
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<SEC-DOCUMENT>0001140361-04-003666.txt : 20040615
<SEC-HEADER>0001140361-04-003666.hdr.sgml : 20040615
<ACCEPTANCE-DATETIME>20040615182825
ACCESSION NUMBER:		0001140361-04-003666
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20040615
FILED AS OF DATE:		20040615

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			GARNREITER MICHAEL
		CENTRAL INDEX KEY:			0001207669

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-24946
		FILM NUMBER:		04865003

	MAIL ADDRESS:	
		STREET 1:		8600 N ORBALLO CIR
		CITY:			PARADISE VALLEY
		STATE:			AZ
		ZIP:			85253

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			KNIGHT TRANSPORTATION INC
		CENTRAL INDEX KEY:			0000929452
		STANDARD INDUSTRIAL CLASSIFICATION:	TRUCKING (NO LOCAL) [4213]
		IRS NUMBER:				860649974
		STATE OF INCORPORATION:			AZ
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		5601 W BUCKEYE RD
		CITY:			PHOENIX
		STATE:			AZ
		ZIP:			85043
		BUSINESS PHONE:		6022692000

	MAIL ADDRESS:	
		STREET 1:		5601 W BUCKEYE RD
		CITY:			PHOENIX
		STATE:			AZ
		ZIP:			85043
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc1.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-06-15</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000929452</issuerCik>
        <issuerName>KNIGHT TRANSPORTATION INC</issuerName>
        <issuerTradingSymbol>KNGT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001207669</rptOwnerCik>
            <rptOwnerName>GARNREITER MICHAEL</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>5601 WEST BUCKEYE ROAD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>PHOENIX</rptOwnerCity>
            <rptOwnerState>AZ</rptOwnerState>
            <rptOwnerZipCode>85043</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Director Stock Option (right to buy)</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>24.56</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2004-06-15</value>
            </transactionDate>
            <deemedExecutionDate>
                <value>2004-06-01</value>
            </deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>500</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>24.56</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2005-01-02</value>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2014-05-31</value>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>500</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Pursuant to the Knight Transportation, Inc. 2003 Stock Option Plan, every June 1 while the plan is in effect, independent directors automatically receive a stock option grant of 500 shares of Knight common stock, the exercise price of which is the fair market value as of June 1.  The stock options granted are not exercisable until seven months after the date of the grant and are forfeitable if the director terminates his service as a director of Knight Transportation, Inc. within one year after the date of the stock option grant.  The stock options expire on the earlier of (a) one year after the director terminates his service as a director of Knight Transportation, Inc., or (b) ten years after the date of the grant.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Michael Garnreiter</signatureName>
        <signatureDate>2004-06-15</signatureDate>
    </ownerSignature>
</ownershipDocument>

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