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

    <schemaVersion>X0304</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2011-12-14</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001519632</issuerCik>
        <issuerName>LRR Energy, L.P.</issuerName>
        <issuerTradingSymbol>LRE</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001524918</rptOwnerCik>
            <rptOwnerName>Farber Jonathan C.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O LIME ROCK MANAGEMENT LP</rptOwnerStreet1>
            <rptOwnerStreet2>274 RIVERSIDE AVENUE, 3RD FLOOR</rptOwnerStreet2>
            <rptOwnerCity>WESTPORT</rptOwnerCity>
            <rptOwnerState>CT</rptOwnerState>
            <rptOwnerZipCode>06880</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common units representing limited partner interests</value>
            </securityTitle>
            <transactionDate>
                <value>2011-12-14</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>171472</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>721558</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Notes</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common units representing limited partner interests</value>
            </securityTitle>
            <transactionDate>
                <value>2011-12-14</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>56852</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>239230</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F5"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Notes</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F5"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common units representing limited partner interests</value>
            </securityTitle>
            <transactionDate>
                <value>2011-12-14</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>971676</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4088812</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F6"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Notes</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F6"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common units representing limited partner interests</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">In connection with the closing of the underwriters' over-allotment on December 14, 2011, LRR Energy, L.P. repurchased an aggregate of 1,200,000 common units from Lime Rock Resources A, L.P. (&quot;LRR A&quot;), Lime Rock Resources B, L.P. (&quot;LRR B&quot;) and Lime Rock Resources C, L.P. (&quot;LRR C&quot;) (the &quot;Units&quot;) at the price to public minus the underwriting discount and structuring fees.</footnote>
        <footnote id="F2">The Reporting Person is one of two managers of LRR GP, LLC (&quot;LRR GP&quot;), which is the general partner of Lime Rock Resources GP, L.P. (&quot;Lime Rock GP&quot;), which is the sole member of each of Lime Rock Resources A GP, LLC (&quot;LRR A GP&quot;) and Lime Rock Resources C GP, LLC (&quot;LRR C GP&quot;).  LRR A GP is the general partner of LRR A, Lime Rock GP is the general partner of LRR B, and LRR C GP is the general partner of LRR C.</footnote>
        <footnote id="F3">The Reporting Person, LRR GP, Lime Rock GP, LRR A GP and LRR C GP may be deemed to share voting and dispositive power over the reported securities.  Each of the Reporting Person, LRR GP, Lime Rock GP, LRR A GP and LRR C GP disclaim beneficial ownership of any interests of the reported securities in excess of such person's or entity's respective pecuniary in the securities.  This report shall not be deemed an admission that the Reporting Person, LRR GP, Lime Rock GP, LRR A GP or LRR C GP is the beneficial owner of such interests for purposes of Section 16 or for any other purpose.</footnote>
        <footnote id="F4">Units owned by LRR A.</footnote>
        <footnote id="F5">Units owned by LRR B.</footnote>
        <footnote id="F6">Units owned by LRR C.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Kris Agarwal, as attorney-in-fact</signatureName>
        <signatureDate>2011-12-16</signatureDate>
    </ownerSignature>
</ownershipDocument>
