A young man has been rushed to hospital after he was stabbed multiple times near a pizza shop.

Emergency services were called to Fetherstone St in Bankstown in Sydney's south-west about 8.30pm on Thursday, following reports a man, 22, had been stabbed in the left leg.

He was treated at the scene by paramedics before he was transported him to hospital in a stable condition.

Investigators have established a 'fairly extensive' crime scene near the restaurant located in the heart of the Bankstown CBD.

Police are still trying to ascertain where the man was stabbed.

Detectives and forensic officers spent the night canvassing the vicinity interviewing witnesses and scouring for evidence.

No arrests or charges have been laid at this stage.

Footage showed paramedics treating the injured man while he laid bleeding on the footpath outside the pizza shop before he was placed onto a stretcher and into the ambulance.

A large pool of blood and an abandoned sneaker seen outside the cordoned off pizza shop.

One witness was on his way to get pizza for dinner when he spotted police cars everywhere.

'There was everyone yelling and I didn't know what to do so I waited outside,' the man said.

Another shocked witness described the incident as very disheartening.

'I would never expect that in the Bankstown area,' he said.