A man is fighting for life after being stabbed on Malvern Road just after midnight. The police station is 100 metres up the same street, and it never closes.

A man is fighting for life after being stabbed on Malvern Road in South Yarra early on Sunday.

Emergency services were called to the road near the corner of Francis Street about 12.20am, after reports a man had been found with serious head injuries.

Police were told he was assaulted before being stabbed.

He was taken to hospital with life-threatening injuries.

No arrests have been made and detectives are still working to establish what happened.

The Prahran police station stands at 396 Malvern Road, about 100 metres from where the man was found.

Its public counter and telephone are staffed 24 hours a day.

The station also houses the Stonnington Crime Investigation Unit, the detectives who take carriage of serious assaults in the area.

They are now investigating one that happened on their own street.

Adam Brierley, who saw the aftermath, told the Herald Sun the scene was "pretty gory".

"I mean, [the offenders] obviously took a big chunk out of the guy, but hopefully he's OK," Mr Brierley said.

Malvern Road runs the length of Prahran and South Yarra and carries a tram line.

The stretch near Francis Street is shops, apartments and a small run of late-trading venues, not far from Chapel Street.

Stonnington detectives have investigated other serious stabbings in the precinct.

Last December a 25-year-old Parkville man was charged after a man was stabbed during an altercation on Commercial Road about 10pm, leaving the victim with life-threatening injuries.

Police have not said whether Sunday's victim and his attackers knew one another, how many people were involved, or whether a weapon has been recovered.

They have asked anyone who saw the incident, or who has CCTV or dashcam footage from the area, to come forward.

Anyone with information can contact Crime Stoppers on 1800 333 000 or make a confidential report at crimestoppersvic.com.au.