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

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2005-08-23</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000105668</issuerCik>
        <issuerName>WENDYS INTERNATIONAL INC</issuerName>
        <issuerTradingSymbol>WEN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001255685</rptOwnerCik>
            <rptOwnerName>CAVA JEFFREY M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>WENDY'S INTERNATIONAL, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>P. O. BOX 256</rptOwnerStreet2>
            <rptOwnerCity>DUBLIN</rptOwnerCity>
            <rptOwnerState>OH</rptOwnerState>
            <rptOwnerZipCode>43017-0256</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>EXECUTIVE VICE PRESIDENT</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>16884</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Phantom Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0</value>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2005-08-23</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F2"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>48.85</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F3"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Shares</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>2</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>872</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">EACH SHARE OF PHANTOM STOCK IS PAYABLE IN 1 SHARE OF COMMON STOCK OF THE ISSUER.</footnote>
        <footnote id="F2">REFLECTS SHARES ACQUIRED PURSUANT TO THE DIVIDEND REINVESTMENT PROVISIONS OF THE ISSUER'S DEFERRED COMPENSATION PLAN.</footnote>
        <footnote id="F3">REFLECTS PHANTOM STOCK ACQUIRED THROUGH PARTICIPATION IN ISSUER'S DEFERRED COMPENSATION PLAN.  PHANTOM STOCK IS PAYABLE IN COMMON STOCK NOT EARLIER THAN SIX MONTHS AFTER TERMINATION OF REPORTING PERSON'S EMPLOYMENT.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>JEFFREY M CAVA</signatureName>
        <signatureDate>2005-08-25</signatureDate>
    </ownerSignature>
</ownershipDocument>
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X0202
4
2005-08-23
0
0000105668
WENDYS INTERNATIONAL INC
WEN
0001255685
CAVA JEFFREY M
WENDY'S INTERNATIONAL, INC.
P. O. BOX 256
DUBLIN
OH
43017-0256
0
1
0
0
EXECUTIVE VICE PRESIDENT
Common Stock
16884
D
Phantom Stock
0
2005-08-23
4
A
0
2
48.85
A
Common Shares
2
872
D
EACH SHARE OF PHANTOM STOCK IS PAYABLE IN 1 SHARE OF COMMON STOCK OF THE ISSUER.
REFLECTS SHARES ACQUIRED PURSUANT TO THE DIVIDEND REINVESTMENT PROVISIONS OF THE ISSUER'S DEFERRED COMPENSATION PLAN.
REFLECTS PHANTOM STOCK ACQUIRED THROUGH PARTICIPATION IN ISSUER'S DEFERRED COMPENSATION PLAN.  PHANTOM STOCK IS PAYABLE IN COMMON STOCK NOT EARLIER THAN SIX MONTHS AFTER TERMINATION OF REPORTING PERSON'S EMPLOYMENT.
JEFFREY M CAVA
2005-08-25