A 16-year-old boy is in a stable condition at Royal North Shore Hospital after he was stabbed in the chest and back near Sydney's Luna Park on Friday night.

Emergency services were called to Luna Park Reserve on Olympic Drive, Milsons Points about 8pm after reports of a stabbing.

A 16-year-old boy was stabbed near Luna Park Credit:SMH

Police said the teenager was with a group of friends heading to the theme park when they were approached by another group, also believed to be teenagers. Police said an altercation took place and the second group ran off.

Paramedics treated the boy at the scene before taking him to hospital.

Investigations are continuing.