-----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,
 VwpnaZlMseKS3zS1vK6Wqg5FFycycIh8fz1C9bXYx90JzMHozsNtMijFQ5pguVG0
 BVkHwINT4UE/a/IwSHTYTQ==

<SEC-DOCUMENT>0001419829-07-000012.txt : 20071203
<SEC-HEADER>0001419829-07-000012.hdr.sgml : 20071203
<ACCEPTANCE-DATETIME>20071203152024
ACCESSION NUMBER:		0001419829-07-000012
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20071129
FILED AS OF DATE:		20071203
DATE AS OF CHANGE:		20071203

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MFS CALIFORNIA INSURED MUNICIPAL FUND
		CENTRAL INDEX KEY:			0001092896
		IRS NUMBER:				043483817
		STATE OF INCORPORATION:			MA
		FISCAL YEAR END:			1130

	BUSINESS ADDRESS:	
		STREET 1:		500 BOYLSTON STREET
		STREET 2:		20TH FL LEGAL DEPT.
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02116
		BUSINESS PHONE:		6179545000

	MAIL ADDRESS:	
		STREET 1:		500 BOYLSTON STREET
		STREET 2:		20TH FL LEGAL DEPT.
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02116

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	COLONIAL CALIFORNIA INSURED MUNICIPAL FUND
		DATE OF NAME CHANGE:	19990927

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	PREMIER CALIFORNIA MUNICIPAL INCOME FUND
		DATE OF NAME CHANGE:	19990809

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Dougherty Kevin
		CENTRAL INDEX KEY:			0001419829

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	811-09537
		FILM NUMBER:		071280485

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		(800)343-2829

	MAIL ADDRESS:	
		STREET 1:		500 BOYLSTON STREET
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02116
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2007-11-29</periodOfReport>

    <noSecuritiesOwned>1</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001092896</issuerCik>
        <issuerName>MFS CALIFORNIA INSURED MUNICIPAL FUND</issuerName>
        <issuerTradingSymbol>CAA</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001419829</rptOwnerCik>
            <rptOwnerName>Dougherty Kevin</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>500 BOYLSTON STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02116</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <ownerSignature>
        <signatureName>Susan S. Newton, By Power of Attorney</signatureName>
        <signatureDate>2007-12-03</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----