UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): March 16, 2006

Chiron Corporation

(Exact name of registrant as specified in its charter)

Delaware	0-12798	94-2754624
(State or other	(Commission	(IRS Employer
jurisdiction of	File Number)	Identification No.)
incorporation)

4560 Horton Street, Emeryville, CA		94608
(Address of principal executive offices)		(Zip Code)

Registrant’s telephone number, including area code (510) 655-8730

N/A

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

o Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

o Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

o Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

o Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Item 2.02 Results of Operations and Financial Condition.

On March 16, 2006, Chiron Corporation (“Chiron”) issued a press release announcing that it has revised its fourth-quarter and year-end December 31, 2005 financial results, previously released on January 31, 2006, as a result of a recall and withdrawal of MORUPAR®, its measles, mumps and rubella vaccine.

A copy of Chiron’s press release of March 16, 2006 is attached hereto as Exhibit 99.1 and is incorporated by reference in this Item 2.02.

The information furnished pursuant to this Item of this Current Report on Form 8-K (including the exhibit hereto) shall not be considered “filed” under the Securities Exchange Act of 1934, as amended, nor shall it be incorporated by reference into any of Chiron’s filings under the Securities Act of 1933, as amended, or under the Securities Exchange Act of 1934, as amended, unless Chiron expressly states in such filing that such information is to be considered “filed” or incorporated by reference therein.

Item 9.01	Financial Statements and Exhibits

(a)	Financial statements of businesses acquired.

	Not applicable.

(b)	Pro forma financial information.

	Not applicable.

(c)	Shell Company transactions.

	Not applicable.

(d)	Exhibits.

	Exhibit Number

	99.1	Press Release issued March 16, 2006.

# # #

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

	CHIRON CORPORATION
	(Registrant)



Date: March 16, 2006	By:		/s/ Ursula B. Bartels
		Ursula B. Bartels
		Vice President, Secretary and
		General Counsel

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