Bell police responded to the call at about 11:50 p.m. Saturday.
Police said the victim got into an argument at a Koreatown bowling alley before he and his girlfriend left in two separate cars.
Investigators said the couple was followed from the bowling alley, and the suspect's car pulled up to them on the 710 Freeway near Florence Avenue. Someone inside that vehicle then opened fire.
The man was shot twice in the back and once in the leg, police said. He was taken to a hospital in stable condition.
Authorities said the woman's car was shot at, but she was not hit.
The gunman is still on the loose. A description was not released.