A man had several teeth knocked out and is believed to have had his jaw broken in an attack at the weekend.
Police were called to the scene of the attack outside Barclays Bank in Epsom High Street at about 2am on Saturday morning.
The victim in his 30s was taken to hospital with facial injuries and a suspected broken jaw.
Detective Constable Gemma Scott said: "I would appeal to anyone who was out in the bars and clubs in Epsom last night who believes they may have information which would assist our investigation to share this with police."
Police are carrying out enquiries and examining CCTV footage.
Anyone with information should call Surrey Police on 101, quoting reference 45140033286, or call Crimestoppers anonymously on 0800 555 111.