No one was injured during the crash, which happened at the corner of Lookout Mountain Avenue and Laurel Canyon Boulevard. The Golden Globe-winning actor, 31, is "fine," says his publicist, Susan Patricola.
Phoenix was driving eastbound on Lookout Mountain at about 2:50 p.m. when he realized his brakes were not working, said police spokesman Officer Jason Lee.
Phoenix lost control of his car, which flipped over and collided with another vehicle also headed in the same direction, Lee said. Both parties exchanged information, and no police report was filed.
Phoenix is still expected to attend the Screen Actors Guild Awards on Sunday, where he is nominated in the best actor category.