Gardaí are appealing for witnesses after two men were assaulted in the People's Park in Waterford city last night.
The brothers are believed to have been attacked by a group of up to five people with hurleys sometime between 11.30pm and midnight.
It is understood the younger brother, aged 24, is in a critical condition in intensive care in Waterford Regional Hospital.
The other brother, 27, is suffering from a suspected broken jaw and bruising to the face and upper body.
The Park has been sealed off for a technical examination. No arrests have so far been made.