-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 AuZMhDPNfVrDxbsmCNOQ6i4u0N3lGXkQcGyNlofxrwARiJVGUH9pEUSaMdpOFRT6
 vwhk1sHqNQ1Xi9sbomHBPA==

<SEC-DOCUMENT>0001463205-10-000005.txt : 20100202
<SEC-HEADER>0001463205-10-000005.hdr.sgml : 20100202
<ACCEPTANCE-DATETIME>20100202195445
ACCESSION NUMBER:		0001463205-10-000005
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20100201
FILED AS OF DATE:		20100202
DATE AS OF CHANGE:		20100202

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			PROVENZANO JOSEPH L
		CENTRAL INDEX KEY:			0001252962

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-19709
		FILM NUMBER:		10568569

	MAIL ADDRESS:	
		STREET 1:		2603 MAIN STREET
		STREET 2:		SUITE 1155
		CITY:			IRVINE
		STATE:			CA
		ZIP:			92653

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			BIOLARGO, INC.
		CENTRAL INDEX KEY:			0000880242
		STANDARD INDUSTRIAL CLASSIFICATION:	CHEMICALS & ALLIED PRODUCTS [2800]
		IRS NUMBER:				650159115
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		2603 MAIN ST.
		STREET 2:		SUITE 1155
		CITY:			IRVINE
		STATE:			CA
		ZIP:			92614
		BUSINESS PHONE:		949-643-9540

	MAIL ADDRESS:	
		STREET 1:		2603 MAIN ST.
		STREET 2:		SUITE 1155
		CITY:			IRVINE
		STATE:			CA
		ZIP:			92614

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	NUWAY MEDICAL INC
		DATE OF NAME CHANGE:	20030205

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	NUWAY ENERGY INC
		DATE OF NAME CHANGE:	20010815

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	LATIN AMERICAN CASINOS INC
		DATE OF NAME CHANGE:	19960520
</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>2010-02-01</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000880242</issuerCik>
        <issuerName>BIOLARGO, INC.</issuerName>
        <issuerTradingSymbol>BLGO</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001252962</rptOwnerCik>
            <rptOwnerName>PROVENZANO JOSEPH L</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>2603 MAIN STREET</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 1155</rptOwnerStreet2>
            <rptOwnerCity>IRVINE</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>92614</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Secretary and V.P. Operations</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Option to Purchase Common Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0.575</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2010-02-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>200000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2010-02-01</value>
            </exerciseDate>
            <expirationDate>
                <value>2020-02-01</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>200000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>330000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <ownerSignature>
        <signatureName>Joseph L. Provenzano</signatureName>
        <signatureDate>2010-02-02</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----