A teenager is recovering in hospital after he was stabbed in the back in Sydney's south.

Police say the 19-year-old man was stabbed following a brawl with a group of males in Rawson Street, Rockdale, soon after 7pm (AEDT) on Wednesday.

He was treated by paramedics at the scene before he was taken to St George Hospital for treatment, where he remains in a stable condition.

Anyone with information about the incident who can assist police with their investigations is urged to contact Crime Stoppers on 1800 333 000.