A young man was brought to University Hospital Waterford for treatment of a stab wound following an assault in the Ballybeg area of Waterford City overnight.
The incident occurred in the early hours of Wednesday morning, at approximately 1.30am.
A man in his 40s was arrested as a result of the altercation.
The man in question was taken to Waterford Garda Station where he is currently being detained under Section 4 of Criminal Justice Act, 1984.