Arnold Schwarzenegger is recovering in a Los Angeles hospital after undergoing heart surgery.
The 70-year-old former California governor had a scheduled procedure to replace a pulmonic valve on Thursday, according to his spokesman.
On Friday he was said to be in a stable condition.
Schwarzenegger was a bodybuilding star before turning to movies. His career as an action hero took off with the box-office hit "Conan the Barbarian" in 1982.
His role in "The Terminator" in 1984 propelled him into box-office superstardom.
He served as governor of California from 2003 to 2011.
He had surgery in 1997 to replace the same heart valve, while a motorcycle crash in 2001 left him with several broken ribs.
He has had a hip replaced and had rotator cuff surgery in 2003.