<SUBMISSION>
<ACCESSION-NUMBER>0001144215-08-000003
<TYPE>4
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20071220
<FILING-DATE>20080114
<DATE-OF-FILING-DATE-CHANGE>20080114
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>ACUITY BRANDS INC
<CIK>0001144215
<ASSIGNED-SIC>5160
<IRS-NUMBER>582632672
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>0831
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>1170 PEACHTREE STREET, NE
<STREET2>SUITE 2400
<CITY>ATLANTA
<STATE>GA
<ZIP>30309-7676
<PHONE>404-853-1400
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>1170 PEACHTREE STREET, NE
<STREET2>SUITE 2400
<CITY>ATLANTA
<STATE>GA
<ZIP>30309-7676
</MAIL-ADDRESS>
<FORMER-COMPANY>
<FORMER-CONFORMED-NAME>L&C SPINCO INC
<DATE-CHANGED>20010629
</FORMER-COMPANY>
</ISSUER>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>MURPHY KENYON W
<CIK>0001183394
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>001-16583
<FILM-NUMBER>08528545
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>C/O AUITY BRANDS INC
<STREET2>1170 PEACHTREE STREET NE STE 2400
<CITY>ATLANTA
<STATE>GA
<ZIP>30309-7649
<PHONE>4048531400
</BUSINESS-ADDRESS>
</REPORTING-OWNER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2007-12-20</periodOfReport>

    <notSubjectToSection16>1</notSubjectToSection16>

    <issuer>
        <issuerCik>0001144215</issuerCik>
        <issuerName>ACUITY BRANDS INC</issuerName>
        <issuerTradingSymbol>AYI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001183394</rptOwnerCik>
            <rptOwnerName>MURPHY KENYON W</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O ACUITY BRANDS INC.</rptOwnerStreet1>
            <rptOwnerStreet2>1170 PEACHTREE ST NE SUITE 2400</rptOwnerStreet2>
            <rptOwnerCity>ATLANTA</rptOwnerCity>
            <rptOwnerState>GA</rptOwnerState>
            <rptOwnerZipCode>30309</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>EVP,CAO and General Counsel</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2007-12-20</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>5</transactionFormType>
                <transactionCode>G</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value>E</value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>235</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>31241</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The total direct shares owned following the reported transaction include 15,178 time-vesting shares.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Kenyon W. Murphy</signatureName>
        <signatureDate>2008-01-14</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
