<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-07-23</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000728535</issuerCik>
        <issuerName>HUNT J B TRANSPORT SERVICES INC</issuerName>
        <issuerTradingSymbol>JBHT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001190245</rptOwnerCik>
            <rptOwnerName>HARPER ALFRED C</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>615 J.B. HUNT CORPORATE DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>LOWELL</rptOwnerCity>
            <rptOwnerState>AR</rptOwnerState>
            <rptOwnerZipCode>72745-</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <officerTitle></officerTitle>
            <otherText>EVP and Chief Operations Offic</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>81111</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock 401(k)</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>8610</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Right to Buy   Stock Option</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>5.31</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2001-06-01</value>
            </exerciseDate>
            <expirationDate>
                <value>2006-10-12</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>2000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Right to Buy   Stock Option</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>6</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2000-06-01</value>
            </exerciseDate>
            <expirationDate>
                <value>2008-01-25</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>14286</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>14286</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Right to Buy   Stock Option</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>6.25</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>1999-06-01</value>
            </exerciseDate>
            <expirationDate>
                <value>2009-10-08</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>9436</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>9436</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Right to Buy   Stock Option</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>6.95</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2002-06-01</value>
            </exerciseDate>
            <expirationDate>
                <value>2012-11-02</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>50000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>50000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Right to Buy   Stock Option</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>7.5</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>1998-06-01</value>
            </exerciseDate>
            <expirationDate>
                <value>2008-04-14</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>20000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>20000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Right to Buy   Stock Option</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>8.81</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>1994-06-01</value>
            </exerciseDate>
            <expirationDate>
                <value>2006-07-20</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>40000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>40000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Right to Buy   Stock Option</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>9.62</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>1997-06-01</value>
            </exerciseDate>
            <expirationDate>
                <value>2007-05-30</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>6000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Right to Buy   Stock Option</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>14.16</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2004-06-01</value>
            </exerciseDate>
            <expirationDate>
                <value>2013-10-24</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>35556</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>35556</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Right to Buy   Stock Option</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>14.43</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>1999-06-01</value>
            </exerciseDate>
            <expirationDate>
                <value>2009-06-15</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>8000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>8000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Right to Buy   Stock Option</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>24.4</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2009-06-01</value>
            </exerciseDate>
            <expirationDate>
                <value>2013-10-23</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>24000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>24000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeTransaction>
            <securityTitle>
                <value>Forward Sale Contract</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>1</value>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2004-07-23</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionTotalValue>
                    <value>1</value>
                    <footnoteId id="F1"/>
                </transactionTotalValue>
                <transactionPricePerShare>
                    <value>1</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2007-07-23</value>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2007-07-23</value>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityValue>
                    <value>1</value>
                    <footnoteId id="F1"/>
                </underlyingSecurityValue>
            </underlyingSecurity>
            <postTransactionAmounts>
                <valueOwnedFollowingTransaction>
                    <value>1</value>
                </valueOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">On July 23, 2004, Alfred C. Harper entered into a 3-year pre-paid forward sales contract (&quot;Contract&quot;) with Merrill Lynch, Pierce, Fenner &amp; Smith, Inc. (&quot;Merrill&quot;).  Pursuant to the Contract, Mr. Harper will sell up to 30,000 shares of Common Stock of J.B. Hunt Transport Services, Inc. to Merrill in July 2007.  In consideration of his agreement under the Contract, Mr. Harper will receive approximately 80% of the proceeds from the sale as a pre-payment.  The actual number of shares that Mr. Harper will deliver depends on the closing price of the common stock at the end of the Contract term.  Mr. Harper had pledged 30,000 shares of common stock to Merrill as security for his obligation to deliver shares at the termination of the Contract.  The pricing terms of the Contract has not been determined.  Mr. Harper will amend this Form 4 at such time as those terms are available.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Debbie Willbanks</signatureName>
        <signatureDate>2004-07-26</signatureDate>
    </ownerSignature>
</ownershipDocument>
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X0202
4
2004-07-23
0
0000728535
HUNT J B TRANSPORT SERVICES INC
JBHT
0001190245
HARPER ALFRED C
615 J.B. HUNT CORPORATE DRIVE
LOWELL
AR
72745-
0
0
0
1
EVP and Chief Operations Offic
Common Stock
81111
D
Common Stock 401(k)
8610
D
Right to Buy   Stock Option
5.31
2001-06-01
2006-10-12
Common Stock
2000
2000
D
Right to Buy   Stock Option
6
2000-06-01
2008-01-25
Common Stock
14286
14286
D
Right to Buy   Stock Option
6.25
1999-06-01
2009-10-08
Common Stock
9436
9436
D
Right to Buy   Stock Option
6.95
2002-06-01
2012-11-02
Common Stock
50000
50000
D
Right to Buy   Stock Option
7.5
1998-06-01
2008-04-14
Common Stock
20000
20000
D
Right to Buy   Stock Option
8.81
1994-06-01
2006-07-20
Common Stock
40000
40000
D
Right to Buy   Stock Option
9.62
1997-06-01
2007-05-30
Common Stock
6000
6000
D
Right to Buy   Stock Option
14.16
2004-06-01
2013-10-24
Common Stock
35556
35556
D
Right to Buy   Stock Option
14.43
1999-06-01
2009-06-15
Common Stock
8000
8000
D
Right to Buy   Stock Option
24.4
2009-06-01
2013-10-23
Common Stock
24000
24000
D
Forward Sale Contract
1
2004-07-23
4
J
0
1
1
A
2007-07-23
2007-07-23
Common Stock
1
1
D
On July 23, 2004, Alfred C. Harper entered into a 3-year pre-paid forward sales contract ("Contract") with Merrill Lynch, Pierce, Fenner & Smith, Inc. ("Merrill").  Pursuant to the Contract, Mr. Harper will sell up to 30,000 shares of Common Stock of J.B. Hunt Transport Services, Inc. to Merrill in July 2007.  In consideration of his agreement under the Contract, Mr. Harper will receive approximately 80% of the proceeds from the sale as a pre-payment.  The actual number of shares that Mr. Harper will deliver depends on the closing price of the common stock at the end of the Contract term.  Mr. Harper had pledged 30,000 shares of common stock to Merrill as security for his obligation to deliver shares at the termination of the Contract.  The pricing terms of the Contract has not been determined.  Mr. Harper will amend this Form 4 at such time as those terms are available.
Debbie Willbanks
2004-07-26