The incident occurred shortly before 6:00 p.m. on 29th and Dauphin streets in North Philadelphia.
Police say three men tried to attack and rob a 49-year-old man on the street.
According to police, in self-defense, the victim stabbed one of the males, a 15-year-old.
The teen was transported to Hahnemann Hospital in stable condition.
No other arrests have been made.
