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

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2005-04-22</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001313550</rptOwnerCik>
            <rptOwnerName>Boone Daniel L</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>SVP &amp; GEN. CONTROLLER</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2005-04-22</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>268</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>40.905</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>20768.135</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>13007.829</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>BY 401(K) PLAN</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Phantom Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2005-04-22</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>0.228</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>0.228</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>110.9947</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">SHARES SHOWN ON TABLE 1 INCLUDE SHARES ACQUIRED PURSUANT TO THE DIVIDEND REINVESTMENT PROVISIONS OF A RESTRICTED STOCK AWARD MADE UNDER THE ISSUER'S 2003 STOCK INCENTIVE PLAN.</footnote>
        <footnote id="F2">THE REPORTED SHARES OF PHANTOM STOCK WERE ACQUIRED UNDER WENDY'S INTERNATIONAL, INC.'S SUPPLEMENTAL EXECUTIVE RETIREMENT PLAN AND ARE TO BE SETTLED IN CASH UPON THE REPORTING PERSON'S RETIREMENT OR OTHER TERMINATION OF SERVICE.


NOTE: TABLE 1 REFLECTS SHARES ACQUIRED THROUGH PARTICIPATION IN ISSUERS 401(K) PLAN AS OF 04/22/2005.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>DANIEL L BOONE</signatureName>
        <signatureDate>2005-04-26</signatureDate>
    </ownerSignature>
</ownershipDocument>
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X0202
4
2005-04-22
0
0000105668
WENDYS INTERNATIONAL INC
WEN
0001313550
Boone Daniel L
WENDY'S INTERNATIONAL, INC.
P. O. BOX 256
DUBLIN
OH
43017-0256
0
1
0
0
SVP & GEN. CONTROLLER
Common Stock
2005-04-22
4
F
0
268
40.905
D
20768.135
D
Common Stock
13007.829
I
BY 401(K) PLAN
Phantom Stock
0
2005-04-22
4
J
0
0.228
0
A
Common Stock
0.228
110.9947
D
SHARES SHOWN ON TABLE 1 INCLUDE SHARES ACQUIRED PURSUANT TO THE DIVIDEND REINVESTMENT PROVISIONS OF A RESTRICTED STOCK AWARD MADE UNDER THE ISSUER'S 2003 STOCK INCENTIVE PLAN.
THE REPORTED SHARES OF PHANTOM STOCK WERE ACQUIRED UNDER WENDY'S INTERNATIONAL, INC.'S SUPPLEMENTAL EXECUTIVE RETIREMENT PLAN AND ARE TO BE SETTLED IN CASH UPON THE REPORTING PERSON'S RETIREMENT OR OTHER TERMINATION OF SERVICE.

NOTE: TABLE 1 REFLECTS SHARES ACQUIRED THROUGH PARTICIPATION IN ISSUERS 401(K) PLAN AS OF 04/22/2005.
DANIEL L BOONE
2005-04-26