Chiron to Release Earnings on Tuesday, January 31, 2006; Conference Call/Audio Webcast to Follow

Chiron Corporation (NASDAQ:CHIR) today announced that it
will release its fourth-quarter 2005 financial results on Tuesday,
January 31, at 4:00 p.m. EST.
   Forty-five minutes later, at 4:45 p.m. EST, as part of its efforts
to ensure full disclosure to all parties, Chiron will webcast an
earnings discussion conference call live from Chiron.com.
   To access either the live conference call webcast or the replay,
please log on to www.chiron.com/webcast. Please connect to the website
at least 15 minutes prior to the conference call to ensure adequate
time to download any necessary software. Webcast replay will be
available for one year after the completion of the call.
   Alternatively, to access the live conference call by phone, please
call [phone] from the United States or Canada or [phone]
from other locations. Telephone replay is available approximately two
hours after the completion of the call through 11:55 p.m. EST,
Tuesday, February 7, 2006. To access the replay, please call (800)
642-1687 from the United States or Canada or [phone] from other
locations. The conference ID number is 4436756.

   About Chiron

   Chiron delivers innovative and valuable products to protect human
health by advancing pioneering science across the landscape of
biotechnology. The company works to deliver on the limitless promise
of science and make a positive difference in people's lives. For more
information, please visit www.chiron.com.