The accident was reported near Brotherhood Way and Head Street just before 6 a.m., CHP Officer Shawn Chase said.
The CHP motorcycle officer was traveling east on Brotherhood Way when he struck a man in his early 20s who was crossing the street against a red light, Chase said.
The pedestrian was taken to San Francisco General Hospital with an injury to his lower left leg. The officer was not injured.
Preliminary reports indicate the pedestrian may have been under the influence of alcohol at the time of the accident.