The shooting was reported around 6:55 p.m. Friday near Cyril Magnin and Eddy streets.
The victim was being assaulted by three other male teens and a female when one of the suspects pulled out a handgun and shot him, according to police.
The boy was struck in the torso and arm by the gunfire and was taken to San Francisco General Hospital to be treated for his injuries, which are considered life-threatening, police said.
The suspects, described as between 14 and 18 years old, fled and had not been found as of this morning, according to police.
Anyone with information about the shooting is encouraged to call the Police Department's anonymous tip line at (415) 575-4444 or send a tip by text message to TIP411 with "SFPD" in the message.