The crash was reported at Third Avenue between Irving Street and Parnassus Avenue at 10:32 a.m., police spokesman Officer Samson Chan said.
Chan said the tow truck had been either removing or returning a car when the car slipped off the truck.
The truck then went out of control and rolled about half a block down Third Avenue, hitting more than a dozen parked cars, Chan said.
About 10 vehicles sustained major damage, he said.
The woman who owns the car that came off the tow truck and another person who was inside one of the parked cars suffered minor injuries, Chan said.
Muni spokesman Judson True said service on the N-Judah line would be disrupted for about an hour. Bus shuttles were carrying Muni riders between Carl Street and Hillway Avenue and Judah Street and 19th Avenue.
