<SEC-DOCUMENT>0001472160-12-000001.txt : 20120110
<SEC-HEADER>0001472160-12-000001.hdr.sgml : 20120110
<ACCEPTANCE-DATETIME>20120110163128
ACCESSION NUMBER:		0001472160-12-000001
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20120108
FILED AS OF DATE:		20120110
DATE AS OF CHANGE:		20120110

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Demopulos Gregory A MD
		CENTRAL INDEX KEY:			0001472160

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-34475
		FILM NUMBER:		12520327

	MAIL ADDRESS:	
		STREET 1:		1420 FIFTH AVENUE
		STREET 2:		SUITE 2600
		CITY:			SEATTLE
		STATE:			WA
		ZIP:			98101-2347

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			OMEROS CORP
		CENTRAL INDEX KEY:			0001285819
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				911663741
		STATE OF INCORPORATION:			WA
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		1420 5TH AVE
		STREET 2:		SUITE 2600
		CITY:			SEATTLE
		STATE:			WA
		ZIP:			98101
		BUSINESS PHONE:		206-676-5000

	MAIL ADDRESS:	
		STREET 1:		1420 5TH AVE
		STREET 2:		SUITE 2600
		CITY:			SEATTLE
		STATE:			WA
		ZIP:			98101
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0304</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2012-01-08</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001285819</issuerCik>
        <issuerName>OMEROS CORP</issuerName>
        <issuerTradingSymbol>OMER</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001472160</rptOwnerCik>
            <rptOwnerName>Demopulos Gregory A MD</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1420 FIFTH AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 2600</rptOwnerStreet2>
            <rptOwnerCity>SEATTLE</rptOwnerCity>
            <rptOwnerState>WA</rptOwnerState>
            <rptOwnerZipCode>98101-2347</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chairman, CEO &amp; President</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>4.1</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2012-01-08</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>260000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2022-01-07</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>260000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>260000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The option vests and becomes exercisable over 48 equal monthly installments, with the first vesting date April 1, 2011. Subsequent installments vest and become exercisable on each monthly anniversary thereafter.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Alex F. Sutter, attorney-in-fact on behalf of Gregory A. Demopulos, M.D.</signatureName>
        <signatureDate>2012-01-10</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
