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

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2007-08-29</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001345432</issuerCik>
        <issuerName>PERFECTENERGY INTERNATIONAL LTD</issuerName>
        <issuerTradingSymbol>PFEN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001407516</rptOwnerCik>
            <rptOwnerName>FAN MIN</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>NO. 479 YOU DONG ROAD</rptOwnerStreet1>
            <rptOwnerStreet2>XINZHUANG TOWN</rptOwnerStreet2>
            <rptOwnerCity>SHANGHAI</rptOwnerCity>
            <rptOwnerState>F4</rptOwnerState>
            <rptOwnerZipCode>201100</rptOwnerZipCode>
            <rptOwnerStateDescription>CHINA</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, $0.001 par value</value>
            </securityTitle>
            <transactionDate>
                <value>2007-08-29</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>516475</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>16703320</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The reporting person acquired the 516,475 shares in connection with the issuer's share exchange transaction with Crown Capital Partners S.A., Perfectenergy International Limited, a private British Virgin Islands corporation (&quot;Perfectenergy BVI&quot;), and the shareholders of Perfectenergy BVI (&quot;BVI Shareholders&quot;) that closed August 8, 2007 pursuant to which the BVI Shareholders, including the reporting person, exchanged their Perfectenergy BVI shares for the shares of the issuer.

The 516,475 shares were transferred from an existing shareholder of the issuer to the reporting person as consideration to further induce this reporting person to close the share exchange transaction.  There was no cash consideration paid for these shares.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Min Fan</signatureName>
        <signatureDate>2007-10-09</signatureDate>
    </ownerSignature>
</ownershipDocument>
