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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2016-05-18</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001437578</issuerCik>
        <issuerName>BRIGHT HORIZONS FAMILY SOLUTIONS INC.</issuerName>
        <issuerTradingSymbol>BFAM</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001040508</rptOwnerCik>
            <rptOwnerName>BAIN CAPITAL INVESTORS LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>200 CLARENDON STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02116</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001379521</rptOwnerCik>
            <rptOwnerName>BCIP Trust Associates III-B</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>JOHN HANCOCK TOWER</rptOwnerStreet1>
            <rptOwnerStreet2>200 CLARENDON ST.</rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02116</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001430079</rptOwnerCik>
            <rptOwnerName>BCIP Associates-G</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>JOHN HANCOCK TOWER</rptOwnerStreet1>
            <rptOwnerStreet2>200 CLARENDON STREET</rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02116</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2016-05-18</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1776021</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>65.42</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>14508838</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"/>
                    <footnoteId id="F6"/>
                    <footnoteId id="F7"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Bain Capital Investors, LLC (&quot;BCI&quot;) is the sole general partner of Bain Capital Partners X, L.P. (&quot;BCP X&quot;), which is the sole general partner of Bain Capital Fund X, L.P. (&quot;Fund X&quot;). As a result, BCP X may be deemed to share voting and dispositive power with respect to the shares of Common Stock held by Fund X. BCP X disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein. On May 18, 2016, Fund X sold 1,754,399 shares of Common Stock. Following such sale, Fund X held 14,341,243 shares of Common Stock.</footnote>
        <footnote id="F2">On May 18, 2016, BCIP Associates III, LLC (&quot;BCIP III&quot;), whose manager is BCIP Associates III (&quot;BCIPA III&quot;), whose managing partner is Boylston Coinvestors, LLC (&quot;Boylston&quot;), sold 12,409 shares of Common Stock. Following such sale, BCIP III held 100,674 shares of Common Stock. BCIPA III may be deemed to share voting and dispositive power with respect to the shares of Common Stock held by BCIP III. BCIPA III disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.</footnote>
        <footnote id="F3">On May 18, 2016, BCIP Associates III-B, LLC (&quot;BCIP III-B&quot;), whose manager is BCIP Associates III-B (&quot;BCIPA III-B&quot;), whose managing partner is Boylston, sold 2,516 shares of Common Stock. Following such sale, BCIP III-B held 18,277 shares of Common Stock. BCIPA III-B may be deemed to share voting and dispositive power with respect to the shares of Common Stock held by BCIP III-B. BCIPA III-B disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.</footnote>
        <footnote id="F4">On May 18, 2016, BCIP T Associates III, LLC (&quot;BCIPT III&quot;), whose manager is BCIP Trust Associates III (&quot;BCIPTA III&quot;), whose managing partner is Boylston, sold 6,018 shares of Common Stock. Following such sale, BCIPT III held 43,714 shares of Common Stock. BCIPTA III may be deemed to share voting and dispositive power with respect to the shares of Common Stock held by BCIPT III. BCIPTA III disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.</footnote>
        <footnote id="F5">On May 18, 2016, BCIP T Associates III-B, LLC (&quot;BCIPT III-B&quot;), whose manager is BCIP Trust Associates III-B (&quot;BCIPTA III-B&quot;), whose managing partner is Boylston, sold 417 shares of Common Stock. Following such sale, BCIPT III-B held 3,027 shares of Common Stock. BCIPTA III-B may be deemed to share voting and dispositive power with respect to the shares of Common Stock held by BCIPT III-B. BCIPTA III-B disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.</footnote>
        <footnote id="F6">On May 18, 2016, BCIP Associates-G (&quot;BCIP G&quot; and together with Fund X, BCIP III, BCIP III-B, BCIPT III AND BCIPT III-B, the &quot;Bain Capital Entities&quot;), whose managing partner is Boylston, sold 262 shares of Common Stock. Following such sale, BCIP G held 1,903 shares of Common Stock.</footnote>
        <footnote id="F7">The governance, investment strategy and decision-making process with respect to the investments held by all of the Bain Capital Entities is directed by the Global Private Equity Board of BCI. As a result, BCI may be deemed to share voting and dispositive power with respect to all of the shares of Common Stock held by the Bain Capital Entities. BCI disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.</footnote>
    </footnotes>

    <remarks>Form 2 of 2</remarks>

    <ownerSignature>
        <signatureName>BY: Bain Capital Investors, LLC, By: /s/ David Humphrey, Name: David Humphrey, Title: Managing Director</signatureName>
        <signatureDate>2016-05-20</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>BCIP Trust Associates III-B, By: Boylston Coinvestors, LLC, as Managing Partner, By: /s/ David Humphrey, Name: David Humphrey, Title: Authorized Signatory</signatureName>
        <signatureDate>2016-05-20</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>BCIP Associates-G, By: Boylston Coinvestors, LLC, as Managing Partner, By: /s/ David Humphrey, Name: David Humphrey, Title: Authorized Signatory</signatureName>
        <signatureDate>2016-05-20</signatureDate>
    </ownerSignature>
</ownershipDocument>
