A man has been stabbed in the arm and leg in a confrontation following a game of Oztag in Sydney's west overnight, police say.

Police and paramedics were called to Ollie Webb Reserve on Pitt Street in Parramatta just before 9.30pm on Wednesday to reports that a man was suffering multiple stab wounds.

A witness said the 26-year-old man was stabbed with a knife during a brawl that broke out at the sporting field, where numerous games of Oztag were being held on Wednesday night.

Paramedics treated the injured man at the scene before taking him to Westmead Hospital in a stable condition.

No one has been arrested over the stabbing. Police are searching for a man who is believed to be known to the injured man. The cause of the confrontation is not yet known.

Officers from the Parramatta Local Area Command searched the sporting field with torches late into the night and spoke to witnesses.

Police have urged anyone who saw the stabbing and who has not already spoken to police to contact Crime Stoppers on 1800 333 000 or use the Crime Stoppers online reporting page.