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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2020-08-19</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000023194</issuerCik>
        <issuerName>COMSTOCK RESOURCES INC</issuerName>
        <issuerTradingSymbol>CRK</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001520346</rptOwnerCik>
            <rptOwnerName>Porter Stuart D</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>185 DARTMOUTH STREET, 7TH FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02116</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001782167</rptOwnerCik>
            <rptOwnerName>Covey Park Holdings LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>185 DARTMOUTH STREET, 7TH FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02116</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2020-08-19</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>9842500</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>5.60</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>19036420</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Covey Park Holdings LLC</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2020-08-20</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>45920</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>18990500</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Covey Park Holdings LLC</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Jordan Tatum Marye (&quot;Marye&quot;) received an award of 22,686 shares of restricted stock on August 22, 2019, which would vest in full on August 22, 2020, and  23,234 shares of restricted stock on June 3, 2020, which would vest in full on June 3, 2021.  Marye served on the Board of Directors of the Issuer as a nominee of Covey Park Holdings LLC (&quot;Holdings&quot;), a stockholder of the Issuer. Marye agreed to transfer to Holdings any director compensation received from the Issuer, including awards made pursuant to grants of restricted stock. These shares were forfeited in connection with his resignation from the Board of Directors of the Issuer.</footnote>
        <footnote id="F2">These shares are owned directly by Holdings. Holdings is managed by a board of managers, a majority of which is appointed by Covey Park Investment Holdings LLC (&quot;Investment Holdings&quot;). Any actions taken by Investment Holdings must be unanimously approved by its members, DCPF VI Oil and Gas Coinvestment Fund LP (&quot;Co-Invest&quot;), Denham Commodity Partners Fund VI LP (&quot;Fund VI&quot;) and Covey Park VI-A Intermediate LP (&quot;Intermediate&quot;).</footnote>
        <footnote id="F3">Co-Invest is managed by its general partner, DCPF VI GP O&amp;G LP (&quot;DCPF GP LP&quot;), which is managed by its general partner, DCPF VI GP O&amp;G LLC (&quot;DCPF GP LLC&quot;). Each of Fund VI and Intermediate is managed by its general partner, Denham Commodity Partners GP VI LP (&quot;GP VI LP&quot;), which is managed by its general partner, Denham GP VI LLC (&quot;GP VI LLC&quot;). Each of GP VI LLC and DCPF GP LLC is controlled by Stuart D. Porter. Accordingly, each of Investment Holdings, Co-Invest, Fund VI, DCPF GP LP, GP VI LP, GP VI LLC, DCPF GP LLC and Stuart D. Porter may be deemed to be the beneficial owner of these shares; however, each disclaims beneficial ownership of such shares in excess of its pecuniary interest therein.</footnote>
    </footnotes>

    <remarks>The reporting persons are jointly filing this Form 4 pursuant to Rule 16(a)-3(j) under the Securities Exchange Act of 1934.</remarks>

    <ownerSignature>
        <signatureName>/s/ Stuart D. Porter</signatureName>
        <signatureDate>2020-08-20</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/  Jordan Marye, Manager, Covey Park Holdings LLC</signatureName>
        <signatureDate>2020-08-20</signatureDate>
    </ownerSignature>
</ownershipDocument>
