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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2014-02-21</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001494448</issuerCik>
        <issuerName>Imperial Holdings, Inc.</issuerName>
        <issuerTradingSymbol>IFT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001067621</rptOwnerCik>
            <rptOwnerName>GOLDSTEIN PHILLIP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O IMPERIAL HOLDINGS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>701 PARK OF COMMERCE BLVD., SUITE 301</rptOwnerStreet2>
            <rptOwnerCity>BOCA RATON</rptOwnerCity>
            <rptOwnerState>FL</rptOwnerState>
            <rptOwnerZipCode>33487</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Senior Convertible Notes</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>6.76</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2014-02-21</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>6302</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1000</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2014-02-21</value>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2019-02-15</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>932249</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6302</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Unless and until the Issuer obtains shareholder approval of the issuance of shares of common stock upon conversion of the notes, the notes are subject to conversion limitations.</footnote>
        <footnote id="F2">Per Note.</footnote>
        <footnote id="F3">The notes are held by certain private investment funds.  Bulldog Investors, LLC (f/k/a Brooklyn Capital Management, LLC) (&quot;BI&quot;) has voting and investment power with respect to such notes.  The reporting person is a principal of BI and of the general partners of certain such investment funds, and is a limited partner in certain of such funds.   The reporting person disclaims beneficial ownership of these notes except to the extent of his pecuniary interest therein.  These totals do not include 2,941 notes that are owned by BI's Special Opportunities Fund since the reporting person has no pecuniary interest therein.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Michael B. Kirwan, Attorney-in-Fact for Phillip Goldstein</signatureName>
        <signatureDate>2014-02-24</signatureDate>
    </ownerSignature>
</ownershipDocument>
