At approx 0010 am on Monday, 26th April, 2011, North Wales Police were called to Edward Henry Street, Rhyl, following reports of an assault.
A 37 year old man was treated by paramedics for head and facial injuries.
The man, who has not been named, was transferred to Walton hospital where he remains in a critical condition.
The scene has been cordoned off by police for forensic examination.
A 23 year old man is helping police with their enquiries.
Police are appealing to the local community for their help in identifying those responsible for the assault and urge anyone with information to contact 101 (if in Wales), 0845 6071001 (Welsh line), 0845 6071002 (English line) or Crimestoppers on 0800 555111.
