A Newhaven man was arrested after reports of a fight at a Peacehaven pub on Friday (June 21).
Just before 7pm police were called to the Sussex Coaster pub on the A259 South Coast Road.
A 39-year-old local man went to the Royal Sussex County Hospital, Brighton, and was discharged after treatment for a facial injury.
A 27-year-old Newhaven man was found nearby by police officers and was arrested on suspicion of causing actual bodily harm.
He was treated at the same hospital for head injuries and was later released on police bail until August 23 while enquiries continue.
Detective Constable Costin Bonell said: “We are already speaking to several witnesses but we would also like to talk to anyone else who was in or around the pub that evening and saw anything of what happened.
“You can contact us by calling 101 and quoting serial 1580 of 21/6. You can also call independent charity Crimestoppers anonymously on 0800 555 111.”