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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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 bL9zHdICr+vL+6o40q5aGg==

<SEC-DOCUMENT>0001228532-10-000038.txt : 20100514
<SEC-HEADER>0001228532-10-000038.hdr.sgml : 20100514
<ACCEPTANCE-DATETIME>20100514143429
ACCESSION NUMBER:		0001228532-10-000038
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20100512
FILED AS OF DATE:		20100514
DATE AS OF CHANGE:		20100514

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			MADDOCK PAUL L JR
		CENTRAL INDEX KEY:			0001244763

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-11590
		FILM NUMBER:		10832483

	MAIL ADDRESS:	
		STREET 1:		375 SO COUNTY RD
		STREET 2:		STE 205
		CITY:			PALM BEACH
		STATE:			FL
		ZIP:			33480

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CHESAPEAKE UTILITIES CORP
		CENTRAL INDEX KEY:			0000019745
		STANDARD INDUSTRIAL CLASSIFICATION:	NATURAL GAS TRANSMISSION & DISTRIBUTION [4923]
		IRS NUMBER:				510064146
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		909 SILVER LAKE BLVD
		STREET 2:		PO BOX 615
		CITY:			DOVER
		STATE:			DE
		ZIP:			19903-0615
		BUSINESS PHONE:		3027346799

	MAIL ADDRESS:	
		STREET 1:		909 SILVER LAKE BLVD
		CITY:			DOVER
		STATE:			DE
		ZIP:			19904
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-05-12</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000019745</issuerCik>
        <issuerName>CHESAPEAKE UTILITIES CORP</issuerName>
        <issuerTradingSymbol>CPK</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001244763</rptOwnerCik>
            <rptOwnerName>MADDOCK PAUL L JR</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>375 SO COUNTY RD</rptOwnerStreet1>
            <rptOwnerStreet2>STE 205</rptOwnerStreet2>
            <rptOwnerCity>PALM BEACH</rptOwnerCity>
            <rptOwnerState>FL</rptOwnerState>
            <rptOwnerZipCode>33480</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>2010-05-12</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>5359</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>31.226</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>25304</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Shares were purchased in the brokerage account, for which this individual is co-trustee, in multiple transactions ranging from $31.2193 to $31.2335 with a weighted average price of $31.226 per share.  The filer can provide, upon request, a detailed breakout of the transactions, including the number of shares purchased at each separate price.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Beth W. Cooper, by Power of Attorney</signatureName>
        <signatureDate>2010-05-14</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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