The NYPD says the boy was stabbed on the basketball court near M.S. 301 on Cauldwell Avenue.
News 12 was told that a knife was not used in the attack, and it is not yet clear what the boy was stabbed with.
Police say they took the victim to Harlem Hospital, where he is making a healthy recovery.
The NYPD says the suspect was last seen wearing blue pants, gray sneakers and a black coat. He ran away from the scene toward East 163rd Street.
The police are asking if anyone saw something to call the NYPD Crime Stoppers at 1-800-577-TIPS.