A 23-year-old man was being questioned tonight after a man was left fighting for his life following an assault.
The 27-year-old victim was attacked in Galway city centre and suffered serious injuries to his head and face.
The beating took place at about 3.25am at the junction of Upper Dominick Street, Henry Street and William Street West.
The injured man was transferred to Beaumont Hospital, Dublin.
The arrested man was being detained under section four of the Criminal Justice Act, 1984.
Gardaí appealed for witnesses who were in the area around the time of the attack to come forward.