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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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 6tLMA6KgFwm8rifRrmvwgg==

<SEC-DOCUMENT>0000029002-05-000029.txt : 20050728
<SEC-HEADER>0000029002-05-000029.hdr.sgml : 20050728
<ACCEPTANCE-DATETIME>20050728164325
ACCESSION NUMBER:		0000029002-05-000029
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20050414
FILED AS OF DATE:		20050728
DATE AS OF CHANGE:		20050728

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			CHEN C H
		CENTRAL INDEX KEY:			0001196527

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	002-25577
		FILM NUMBER:		05981678

	MAIL ADDRESS:	
		STREET 1:		C/O DIODES INC
		STREET 2:		3050 E HILLCREST DR
		CITY:			WESTLAKE
		STATE:			CA
		ZIP:			91362

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			DIODES INC /DEL/
		CENTRAL INDEX KEY:			0000029002
		STANDARD INDUSTRIAL CLASSIFICATION:	SEMICONDUCTORS & RELATED DEVICES [3674]
		IRS NUMBER:				952039518
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		3050 E HILLCREST DR
		CITY:			WESTLAKE VILLAGE
		STATE:			CA
		ZIP:			91362
		BUSINESS PHONE:		8054464800

	MAIL ADDRESS:	
		STREET 1:		3050 E HILLCREST DR SUITE 200
		STREET 2:		3050 E HILLCREST DR SUITE 200
		CITY:			WESTLAKE VILLAGE
		STATE:			CA
		ZIP:			913623154
</SEC-HEADER>
<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>2005-04-14</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000029002</issuerCik>
        <issuerName>DIODES INC /DEL/</issuerName>
        <issuerTradingSymbol>DIOD</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001196527</rptOwnerCik>
            <rptOwnerName>CHEN C H</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O DIODES INC</rptOwnerStreet1>
            <rptOwnerStreet2>3050 E HILLCREST DR</rptOwnerStreet2>
            <rptOwnerCity>WESTLAKE</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>91362</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2005-04-14</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F4"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>40000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>40000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Common Stock (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>25.95</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2005-04-14</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>37500</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2006-04-14</value>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <value>2015-04-14</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>37500</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>282500</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Shares granted under the Company's Incentive Bonus Plan.</footnote>
        <footnote id="F2">Options granted under Rule 16b-3 Plan.</footnote>
        <footnote id="F3">Options exercisable in 3 equal annual installments beginning 04/14/2006.</footnote>
        <footnote id="F4">Under the terms of the Incentive Bonus Plan, 50% of the shares will become salable and transferable on the day following the third anniversary of Mr. Chen's appointment, and 50% will become salable and transferable on the day following the fourth anniversary of such appointment.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Carl C. Wertz as Power of Attorney for C.H. Chen</signatureName>
        <signatureDate>2005-07-28</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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