The victim was heading home from Edward A. Hall Middle School around 4:30 p.m. when an unknown number of suspects approached him at California Street and Tuttle Avenue, Watsonville police Sgt. Brian Ridgway said.
The suspects, described as males in their late teens and early 20s, assaulted and stabbed the suspect at least once in his upper torso, according to Ridgway.
A resident in the area called police and the victim was taken to a local hospital before being flown to a regional medical center for treatment.
Ridgway said the motive of the stabbing is under investigation, and that it may be gang-related or case of mistaken identity.
No arrests have been made in the case.