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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2017-06-16</periodOfReport>

    <dateOfOriginalSubmission>2017-06-20</dateOfOriginalSubmission>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001006424</issuerCik>
        <issuerName>BEAR STATE FINANCIAL, INC.</issuerName>
        <issuerTradingSymbol>BSF</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001610968</rptOwnerCik>
            <rptOwnerName>Horton Daniel C.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>900 S. SHACKLEFORD ROAD</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 605</rptOwnerStreet2>
            <rptOwnerCity>LITTLE ROCK</rptOwnerCity>
            <rptOwnerState>AR</rptOwnerState>
            <rptOwnerZipCode>72211</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Restricted Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2017-06-16</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2066</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F3"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>2066</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2479</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Restricted stock units convert into common stock on a one-for-one basis.</footnote>
        <footnote id="F2">This amendment is being filed to amend Form 4 filed June 20, 2017, which inadvertently indicated that the subject derivative securities were &quot;Acquired (A),&quot; rather than &quot;Disposed of (D)&quot; (Table II, Column 5. - Number of Derivative Securities Acquired (A) or Disposed of (D)).</footnote>
        <footnote id="F3">On June 16, 2014, the reporting person was granted 3,100 restricted stock units (subsequently adjusted to 3,444 restricted stock units following the Company's 1-for-9 stock dividend in December 2014), vesting 60% on the third anniversary of the grant date, with the remainder vesting in two equal installments on the fourth and fifth anniversaries of the grant date. In a prior filing, the reporting person inadvertently reported an incorrect grant date of June 13, 2014 for this award, instead of the actual grant date of June 16, 2014.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Daniel C. Horton by Brenda Jackson, Attorney-in-Fact</signatureName>
        <signatureDate>2017-06-21</signatureDate>
    </ownerSignature>
</ownershipDocument>
