The collision occurred shortly before 4 a.m. in the 2000 block of Jerrold Avenue at the San Francisco Wholesale Produce Market, according to fire officials.
The driver of the forklift was injured when he was thrown from his seat. Two occupants in the car were also injured. All three were transported to San Francisco General Hospital shortly before 4:15 a.m., a fire dispatcher said.
Two of the people suffered serious injuries and the third suffered moderate injuries, a fire dispatcher said.
The cause of the collision remains under investigation, police said.