The pedestrian was hit shortly before 6 a.m. on Mason Street near Broadway and was transported to San Francisco General Hospital, spokesman Judson True said.
True did not know the extent of the pedestrian's injuries.
Cable car service on the Mason Street portion of the Powell-Mason line was disrupted for more than an hour because of the collision, True said.
The Powell-Mason line begins at the Powell/Market turntable, and runs up and over Nob Hill down to Bay Street at Fisherman's Wharf.
