-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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 hIv9TUnreVE7G0sQna9Umg==

<SEC-DOCUMENT>0000945565-10-000004.txt : 20101223
<SEC-HEADER>0000945565-10-000004.hdr.sgml : 20101223
<ACCEPTANCE-DATETIME>20101223151931
ACCESSION NUMBER:		0000945565-10-000004
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20101221
FILED AS OF DATE:		20101223
DATE AS OF CHANGE:		20101223

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			FX ENERGY INC
		CENTRAL INDEX KEY:			0000907649
		STANDARD INDUSTRIAL CLASSIFICATION:	CRUDE PETROLEUM & NATURAL GAS [1311]
		IRS NUMBER:				870504461
		STATE OF INCORPORATION:			NV
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		3006 HIGHLAND DR
		STREET 2:		STE 206
		CITY:			SALT LAKE CITY
		STATE:			UT
		ZIP:			84106
		BUSINESS PHONE:		801-486-5555

	MAIL ADDRESS:	
		STREET 1:		3006 HIGHLAND DR
		STREET 2:		STE 206
		CITY:			SALT LAKE CITY
		STATE:			UT
		ZIP:			84106

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	FRONTIER OIL EXPLORATION CO
		DATE OF NAME CHANGE:	19940223

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			PIERCE ANDREW W
		CENTRAL INDEX KEY:			0000945565

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-35012
		FILM NUMBER:		101272115

	MAIL ADDRESS:	
		STREET 1:		3006 HIGHLAND DR
		STREET 2:		STE 206
		CITY:			SALT LAKE CITY
		STATE:			UT
		ZIP:			84106
</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>2010-12-21</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000907649</issuerCik>
        <issuerName>FX ENERGY INC</issuerName>
        <issuerTradingSymbol>FXEN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000945565</rptOwnerCik>
            <rptOwnerName>PIERCE ANDREW W</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>3006 HIGHLAND DR</rptOwnerStreet1>
            <rptOwnerStreet2>STE 206</rptOwnerStreet2>
            <rptOwnerCity>SALT LAKE CITY</rptOwnerCity>
            <rptOwnerState>UT</rptOwnerState>
            <rptOwnerZipCode>84106</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Vice President</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-12-21</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>37500</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>282896</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>35000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By IRA</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>57706</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By 401(k)</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">This restricted stock award vests in three equal annual installments beginning December 21, 2011.</footnote>
        <footnote id="F2">Includes 12,500 restricted shares that vest on December 21, 2011, 25,000 restricted shares that vest in two equal annual installments beginning December 21, 2011 and 37,500 restricted shares that vest in three equal annual installments beginning December 21, 2011.</footnote>
        <footnote id="F3">Shares contributed by the issuer to the reporting person 401(k) account.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Andrew W. Pierce</signatureName>
        <signatureDate>2010-12-23</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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