A spokesperson for the star said Sinise was a passenger in a car involved in an accident last Friday. She did not give details about the extent of his injuries.
The 57-year-old was set to perform with his band at a fundraising event in Martinsville, Va. last weekend and in Palm Desert next week.
The Martinsville concert will be rescheduled and the Palm Desert performance has been canceled.
Sinise stars on CBS's "CSI: NY." The show has completed production for the season and won't be affected by the actor's injuries.
The Associated Press contributed to this report.