A 49-year-old man was tonight being questioned over a vicious attack which left a man with serious head injuries.
Gardaí said a 51-year-old man was set upon in a premises on Barrack Street, Waterford city, last night.
He was badly beaten and was taken to the local regional hospital and later transferred to Cork University Hospital.
One man was arrested at the scene and was taken to Waterford garda station where he was being held under section four of the Criminal Justice Act.
Gardaí said the attack took place between 11.30pm and 11.50pm and appealed for anyone who was in the Barrack Street area around the time and may have information to come forward.