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

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-03-03</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000866970</issuerCik>
        <issuerName>LIGHTING SCIENCE GROUP CORP</issuerName>
        <issuerTradingSymbol>LSCG.PK</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000313216</rptOwnerCik>
            <rptOwnerName>KONINKLIJKE PHILIPS ELECTRONICS NV</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>BREITNER CENTER</rptOwnerStreet1>
            <rptOwnerStreet2>AMSTELPLEIN 2</rptOwnerStreet2>
            <rptOwnerCity>AMSTERDAM</rptOwnerCity>
            <rptOwnerState>P7</rptOwnerState>
            <rptOwnerZipCode>1096 BC</rptOwnerZipCode>
            <rptOwnerStateDescription>NETHERLANDS</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Series D Non-Convertible Preferred Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-03-03</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>C</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>5330482</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5330482</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Convertible Note</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>1.006</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2010-03-03</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>C</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>5330482</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2010-03-03</value>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2010-03-03</value>
                <footnoteId id="F3"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Units</value>
                    <footnoteId id="F1"/>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>5330482</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Warrant</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>12.00</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2010-03-03</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>C</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>5330482</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2010-03-03</value>
            </exerciseDate>
            <expirationDate>
                <value>2022-03-03</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>5330482</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5330482</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">On August 27, 2009, in connection with a litigation settlement, the Issuer issued to the Reporting Person the Convertible Note in an aggregate amount of $5,000,000 in consideration of a $5,000,000 loan made by the Reporting Person to the Issuer.  On March 3, 2010, the Convertible Note was automatically converted into Units of the Issuer, on which date the outstanding aggregate principal and interest amount of the Convertible Note was $5,362,465.75.   Each Unit consists of (i) one share of the Issuer's Series D Non-Convertible Preferred Stock, and (ii) a Warrant to purchase one share of the Issuer's Common Stock.  After the conversion of the Convertible Note into the Units, the Reporting Person received 5,330,482 Units, which consist of (i) 5,330,482 shares of the Issuer's Series D Non-Convertible Preferred Stock, and (ii) Warrants to purchase 5,330,482 shares of the Issuer's Common Stock.</footnote>
        <footnote id="F2">The Convertible Note was not convertible at the option of the Reporting Person until the Certificate of Designation for the Series D Non-Convertible Preferred Stock was filed by the Issuer and became effective, as contemplated by the Convertible Note. The Convertible Note was not automatically convertible until the rights offering, as contemplated by the Convertible Note, was consummated or until the first business day following the date on which the Issuer provided the Reporting Person with written notice that Pegasus Partners IV, L.P. had converted its convertible note into Units. The rights offering, as contemplated by the Convertible Note, was consummated on March 3, 2010.</footnote>
        <footnote id="F3">The maturity date was the earliest of July 31, 2010 or the consummation of the rights offering, as contemplated by the Convertible Note or the first business day following the date on which the Issuer provided the Reporting Person with written notice that Pegasus Partners IV, L.P. had converted its convertible note into Units. The rights offering, as contemplated by the Convertible Note, was consummated on March 3, 2010.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Marcio Barbosa, Vice President and Corporate Treasury on behalf of Koninklijke Philips Electronics N.V.</signatureName>
        <signatureDate>2010-03-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
