-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 Ay4AT+WZvuJE9+pBSMCu/PMGbZgRbIBGBEkq/O4OTxGWBS45pUoH/4gECmIPxNmU
 m23zZtuMLul4hilb9mORzA==

<SEC-DOCUMENT>0001065860-10-000028.txt : 20100902
<SEC-HEADER>0001065860-10-000028.hdr.sgml : 20100902
<ACCEPTANCE-DATETIME>20100902161857
ACCESSION NUMBER:		0001065860-10-000028
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20100901
FILED AS OF DATE:		20100902
DATE AS OF CHANGE:		20100902

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Glick Stephen
		CENTRAL INDEX KEY:			0001468306

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-16265
		FILM NUMBER:		101055214

	MAIL ADDRESS:	
		STREET 1:		1280 LANDMEIER RD
		CITY:			ELK GROVE VILLAGE
		STATE:			IL
		ZIP:			60007

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			LIME ENERGY CO.
		CENTRAL INDEX KEY:			0001065860
		STANDARD INDUSTRIAL CLASSIFICATION:	ELECTRONIC & OTHER ELECTRICAL EQUIPMENT (NO COMPUTER EQUIP) [3600]
		IRS NUMBER:				364197337
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		1280 LANDMEIER ROAD
		CITY:			ELK GROVE
		STATE:			IL
		ZIP:			60007
		BUSINESS PHONE:		8474371666

	MAIL ADDRESS:	
		STREET 1:		1280 LANDMEIER ROAD
		CITY:			ELK GROVE VILLAGE
		STATE:			IL
		ZIP:			60007

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	ELECTRIC CITY CORP
		DATE OF NAME CHANGE:	19990907
</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>2010-09-01</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001065860</issuerCik>
        <issuerName>LIME ENERGY CO.</issuerName>
        <issuerTradingSymbol>LIME</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001468306</rptOwnerCik>
            <rptOwnerName>Glick Stephen</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1280 LANDMEIER RD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>ELK GROVE VILLAGE</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60007</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>2010-09-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1403</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>3.23</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>25689</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <ownerSignature>
        <signatureName>Jeffrey Mistarz, by power of attorney</signatureName>
        <signatureDate>2010-09-02</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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