The shooting happened around 7:15 p.m. Friday in the 1500 block of Belle Street.
Authorities said the teenager, Steven Guzman, was standing with a group of people in front of a house when someone in a passing car opened fire on them. The teen was shot in the head and was in the hospital in grave condition.
There's no description yet of the suspects or vehicle.
Anyone with information is urged to call the San Bernardino Police Department at 909- 384-5762.