A man bleeding heavily with severed fingers and a missing kneecap was found in the driveway of a house on the Mornington Peninsula.

He was attacked during a fight between two groups in Rosebud West on Tuesday night, police said.

Another man was shot in the leg during the brawl and he later turned up at a local GP clinic for help but left when doctors said he needed an ambulance.

The man with the severed fingers reportedly staggered to nearby houses and begged residents to take him to a hospital and not to call an ambulance.

He was eventually airlifted to hospital where he is in a serious but stable condition.

Police were yet to talk to him on Wednesday night.

Witness Beck Waters found the man in her driveway when she returned home from the shops.

"He said that he was missing fingers, but I saw his knee and it was ghastly," Ms Waters told the Seven Network on Wednesday.

"You could see right down to the joint because the kneecap wasn't there anymore."

The Armed Crime Squad believe the two groups are known each other. No arrests have been made.

Police want to speak to the driver of a dark Commodore seen at the incident.