A man suffered a broken jaw, two broken teeth and a cut to his left ear during an unprovoked attack.
The victim was walking in Shakespeare Street in Nottingham city centre when a man walked up to him and punched him.
It left him requiring four hours of surgery to realign his jaw and he was unable to eat solid food for three weeks.
Police have released CCTV of a man they would like to speak to in connection with the incident, which happened at around 5.10pm on 24 August.
Detective Sergeant Jon Kerry said: “This was an unprovoked attack that left the victim with very nasty injuries.
“We believe the man pictured in this image may be able to help us with our enquiries and would like to speak with anyone who recognises him.”
Anyone with information is asked to call 101 quoting incident 506 of 24 August.