The New York Post reports the former California governor posted on Twitter that he got a little banged up on the set Thursday of "The Last Stand," in which he portrays a small town sheriff who takes on a drug kingpin.
Schwarzenegger thanked the medical staff who returned him to action an hour later.
A photo shows what appears to be a bloody cut running down from the middle of Schwarzenegger's forehead.
Schwarzenegger did not provide details of what happened.
Schwarzenegger has also been posting tweets and pictures about his offset activities, which have included sightseeing and shopping for warm clothing for cast members.