Police are appealing for information after a man was left unconscious in the High Street in Buckingham in the early hours of Saturday morning.
Police are treating the incident, which happened between 1am and 1.30am on July 7 as grevious bodily harm.
The victim, a man in his twenties, was punched in the face.
He fell to the floor and was knocked unconscious.
As a result of the assault he suffered facial injuries and was taken to Milton Keynes University Hospital and later Luton & Dunstable Hospital.
He has since been discharged.
The offender is described as being a man in his early twenties with tanned skin and an Irish accent.
He was dressed in a dark t-shirt, white shorts, a white baseball cap and black trainers.
Investigating Officer PC Lisa Murton said: “This was a nasty assault which left the victim unconscious and in need hospital treatment.
“I am appealing for any witnesses who may have seen or heard anything to come forward and get in touch.”
Anyone with information is asked to call 101, quoting reference number ‘43180205827’ or to contact Crimestoppers anonymously on 0800 555 111.