-----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,
 TCTS5DeZBrArrE8/MXXp2zq382Dtb5yqDTSHqijqgX0a1x1tHuidelcdBvmmoKgI
 hInYbRNLogB1xxBb5PZsHA==

<SEC-DOCUMENT>0001179110-06-021721.txt : 20061114
<SEC-HEADER>0001179110-06-021721.hdr.sgml : 20061114
<ACCEPTANCE-DATETIME>20061114175523
ACCESSION NUMBER:		0001179110-06-021721
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20061109
FILED AS OF DATE:		20061114
DATE AS OF CHANGE:		20061114

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			THERMO FISHER SCIENTIFIC INC.
		CENTRAL INDEX KEY:			0000097745
		STANDARD INDUSTRIAL CLASSIFICATION:	MEASURING & CONTROLLING DEVICES, NEC [3829]
		IRS NUMBER:				042209186
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		81 WYMAN ST
		STREET 2:		PO BOX 9046
		CITY:			WALTHAM
		STATE:			MA
		ZIP:			02451
		BUSINESS PHONE:		7816221000

	MAIL ADDRESS:	
		STREET 1:		81 WYMAN ST
		STREET 2:		PO BOX 9046
		CITY:			WALTHAM
		STATE:			MA
		ZIP:			02451

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	THERMO ELECTRON CORP
		DATE OF NAME CHANGE:	19920703

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			SPERLING SCOTT M
		CENTRAL INDEX KEY:			0001214212

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-08002
		FILM NUMBER:		061217305

	BUSINESS ADDRESS:	
		STREET 1:		C/O THOMAS H LEE PARTNERS LP
		STREET 2:		75 STATE ST
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02109
		BUSINESS PHONE:		6172271050

	MAIL ADDRESS:	
		STREET 1:		C/O THOMAS H. LEE PARTNERS, L.P.
		STREET 2:		100 FEDERAL STREET, 35TH FLOOR
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02110
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 3 -
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2006-11-09</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000097745</issuerCik>
        <issuerName>THERMO FISHER SCIENTIFIC INC.</issuerName>
        <issuerTradingSymbol>TMO</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001214212</rptOwnerCik>
            <rptOwnerName>SPERLING SCOTT M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O THOMAS H. LEE PARTNERS, L.P.</rptOwnerStreet1>
            <rptOwnerStreet2>100 FEDERAL STREET, 35TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02110</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes></footnotes>

    <ownerSignature>
        <signatureName>/s/ Scott M. Sperling</signatureName>
        <signatureDate>2006-11-14</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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