A police spokesman identified the victim as 30-year-old Lamar Brown of west Philadelphia.
Fire crews were called to Fairmount Park at about 2:15 a.m. Saturday and found a vehicle that had run off the avenue and struck a tree.
Crews freed the victim and rushed him to Hahnemann University Hospital, where the victim was pronounced dead shortly after arrival.
Police said emergency room doctors found a gunshot wound in Brown's neck. Investigators also found several bullet holes in the victim's badly damaged car.
They believe the gunfire occurred elsewhere and have been trying to find the shooting scene.