It happened just after 3 a.m. Sunday morning in the 7900 block of Craig Street.
Police say a man and woman were walking to the car, returning from a local bar, when they were approached by several men wearing ski masks.
At least one of the men was armed with a handgun.
Police say the masked men demanded money from the man, who turned over $500.
During the robbery, one of the suspects fired a shot before fleeing the scene in a dark-colored sedan.
No injuries were reported.
Anyone with information on the suspects is asked to call police at 215-686-TIPS.