The attack happened in the Flax Street area early hours of this morning.
Police received a report of a man, aged in his 40’s, having been assaulted in the street outside licensed premises by a number of unknown persons at around 5.25 am.
He sustained head injuries as a result of the assault.
The victim was taken to hospital where he is said to be in a critical but stable condition.
Detective Inspector Heather Whoriskey has appealed to anyone who was in the area at the time of the assault and who has any information which may be of assistance to the investigation to contact detectives in Musgrave on 101 quoting reference 335 17/07/16.
Information can also be given anonymously through the independent charity Crimestoppers on 0800 555 111.