It happened around 4 p.m. on the 1500 block of Erie Avenue.
Police say the incident started with an altercation and then it escalated.
The 16-year-old victim was stabbed in the shoulder and abdomen.
He made it to Broad Street and Girard Avenue, where he was then rushed to Children's Hospital of Philadelphia. He is listed in stable condition.
No arrests have been made.
Anyone with information is asked to call police at 215-686-TIPS.