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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2016-05-03</periodOfReport>

    <issuer>
        <issuerCik>0001144980</issuerCik>
        <issuerName>ASBURY AUTOMOTIVE GROUP INC</issuerName>
        <issuerTradingSymbol>ABG</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001105497</rptOwnerCik>
            <rptOwnerName>MSD CAPITAL L P</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>645 FIFTH AVENUE, 21ST FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10022</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001217005</rptOwnerCik>
            <rptOwnerName>MSD SBI LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>645 FIFTH AVENUE, 21ST FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10022</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000908724</rptOwnerCik>
            <rptOwnerName>DELL MICHAEL S</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O DELL INC</rptOwnerStreet1>
            <rptOwnerStreet2>ONE DELL WAY</rptOwnerStreet2>
            <rptOwnerCity>ROUND ROCK</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>78682</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2016-05-03</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>225000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>58.12</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2000596</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2016-05-03</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>100</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>58.12</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2000696</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3253</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnotes</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                    <footnoteId id="F5"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Total Return Equity Swap</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>58.12</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2016-05-03</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>1</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>225000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F6"/>
                    <footnoteId id="F7"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F6"/>
                <footnoteId id="F7"/>
            </exerciseDate>
            <expirationDate>
                <value>2017-06-06</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>225000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>225000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                    <footnoteId id="F6"/>
                    <footnoteId id="F7"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">This statement is jointly filed by and on behalf of each of MSD Capital, L.P. (&quot;MSD Capital&quot;), MSD SBI, L.P. (&quot;MSD SBI&quot;) and Michael S. Dell. MSD Capital is the general partner of MSD SBI and may be deemed to beneficially own securities owned by MSD SBI. MSD Capital Management LLC (&quot;MSD Capital Management&quot;) is the general partner of MSD Capital and may be deemed to beneficially own securities owned by MSD Capital. Each of Glenn R. Fuhrman and Marc R. Lisker is a manager of MSD Capital Management and may be deemed to beneficially own securities owned by MSD Capital Management. Michael S. Dell is the controlling member of MSD Capital Management and may be deemed to beneficially own securities owned by MSD Capital Management. Each of Messrs. Dell, Fuhrman, and Lisker disclaims beneficial ownership of such securities except to the extent of any pecuniary interest therein. [footnote cont'd]</footnote>
        <footnote id="F2">[continuation] Mr. Alsfine who is a partner in MSD Capital, was appointed to the Issuer's board of directors and each reporting person may be deemed to beneficially own securities owned by Mr. Alsfine.</footnote>
        <footnote id="F3">Each reporting person states that neither the filing of this statement nor anything herein shall be deemed an admission that such person is, for purposes of Section 16 of the Securities Exchange Act of 1934, as amended (the &quot;Act&quot;), or otherwise, the beneficial owner of any securities covered by this statement. Each reporting person disclaims beneficial ownership of the securities covered by this statement, except to the extent of the pecuniary interest of such person in such securities.</footnote>
        <footnote id="F4">Each reporting person may be deemed to be a member of a group with respect to the issuer or securities of the issuer for purposes of Section 13(d) or 13(g) of the Act. Each reporting person declares that neither the filing of this statement nor anything herein shall be construed as an admission that such person is, for the purposes of Section 13(d) or 13(g) of the Act or any other purpose, a member of a group with respect to the issuer or securities of the issuer.</footnote>
        <footnote id="F5">Represents shares owned by Joel Alsfine, a director of the issuer and a partner in MSD Capital.</footnote>
        <footnote id="F6">On May 3, 2016, simultaneous with the disposition reported in Table I, MSD SBI entered into a cash-settled total return equity swap (&quot;Total Return Swap&quot;) with Goldman Sachs International (&quot;Goldman&quot;) with a reference price of $58.12. Under the terms of the Total Return Swap (i) MSD SBI will be obligated to pay to Goldman any negative price performance of the 225,000 shares of common stock subject to the Total Return Swap as of the expiration date of the Total Return Swap, plus financing, and (ii) Goldman will be obligated to pay to MSD SBI any positive price performance of the 225,000 shares of common stock subject to the Total Return Swap as of the expiration date of such Total Return Swap. Any dividends received by Goldman on the 225,000 shares of common stock during the term of the Total Return Swap will be paid to MSD SBI.</footnote>
        <footnote id="F7">All balances will be cash settled at the expiration date of the Total Return Swap.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>MSD Capital, L.P.
By: MSD Capital Management LLC
Its: General Partner
By: /s/ Marc R. Lisker                                                                Name: Marc R. Lisker
Title: Manager</signatureName>
        <signatureDate>2016-05-05</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>MSD SBI, L.P.
By: MSD Capital, L.P.
Its: General Partner
By: MSD Capital Management LLC
Its: General Partner
By: /s/ Marc R. Lisker
Name: Marc R. Lisker
Title: Manager</signatureName>
        <signatureDate>2016-05-05</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Michael S. Dell
By: /s/ Marc R. Lisker
Name: Marc R. Lisker
Title: Attorney-in-Fact</signatureName>
        <signatureDate>2016-05-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
