Police believe the 25-year-old victim was assaulted by three or four men at about 10pm on Friday night in North Belfast.
The savage attack took place on the Limestone Road close to Mileriver Street.
The injured man’s condition is being described as “critical”.
PSNI Detective Sergeant Melanie McGrory said: “At approximately 10 pm, police received a report that a 25 year old man had been assaulted in the Limestone Road area, close to Mileriver Street.
“It is believed that he may have been assaulted by three or four other males. The man has been taken to hospital for treatment to his injuries which are currently described as critical.
“I would ask anyone with any information about this incident to contact CID at Antrim Road Police Station on the non emergency number 101.
“Or if someone would prefer to provide information without giving their details, they can contact the independent charity Crimestoppers and speak to them anonymously on 0800 555 111.”