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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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<SEC-DOCUMENT>0000787250-05-000037.txt : 20051004
<SEC-HEADER>0000787250-05-000037.hdr.sgml : 20051004
<ACCEPTANCE-DATETIME>20051004085837
ACCESSION NUMBER:		0000787250-05-000037
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20050930
FILED AS OF DATE:		20051004
DATE AS OF CHANGE:		20051004

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			DPL INC
		CENTRAL INDEX KEY:			0000787250
		STANDARD INDUSTRIAL CLASSIFICATION:	ELECTRIC & OTHER SERVICES COMBINED [4931]
		IRS NUMBER:				311163136
		STATE OF INCORPORATION:			OH
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		1065 WOODMAN DRIVE
		CITY:			DAYTON
		STATE:			OH
		ZIP:			45432
		BUSINESS PHONE:		937 259 7142

	MAIL ADDRESS:	
		STREET 1:		1065 WOODMAN DRIVE
		CITY:			DAYTON
		STATE:			OH
		ZIP:			45432

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			LYLES LESTER L
		CENTRAL INDEX KEY:			0001267887

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-09052
		FILM NUMBER:		051119457

	MAIL ADDRESS:	
		STREET 1:		C/O MTC TECHNOLOGIES INC
		STREET 2:		4032 LINDEN AVENUE
		CITY:			DAYTON
		STATE:			OH
		ZIP:			45432
</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>2005-09-30</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000787250</issuerCik>
        <issuerName>DPL INC</issuerName>
        <issuerTradingSymbol>DPL</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001267887</rptOwnerCik>
            <rptOwnerName>LYLES LESTER L</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O DPL INC.</rptOwnerStreet1>
            <rptOwnerStreet2>1065 WOODMAN DRIVE</rptOwnerStreet2>
            <rptOwnerCity>DAYTON</rptOwnerCity>
            <rptOwnerState>OH</rptOwnerState>
            <rptOwnerZipCode>45432</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Restricted Share Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2005-09-30</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F2"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>305</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>26.12</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>DPL Inc. Common Shares</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>305</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5844</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See</value>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">1-for-1.</footnote>
        <footnote id="F2">Deferral of Directors fees into restricted share units representing DPL Inc. common shares pursuant to the Dayton Power and Light Company Directors Deferred Compensation Plan.  Restricted share units are payable in shares of DPL Inc. common stock on a 1-for-1 basis in accordance with the Director's election pursuant to the plan.</footnote>
        <footnote id="F3">Includes dividend equivalents.</footnote>
        <footnote id="F4">Directors Deferred Compensation Plan.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Ellen S. Leffak by Power of Attorney</signatureName>
        <signatureDate>2005-10-04</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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