He was involved in an “altercation” between a group of people on Candie Road in St Peter Port in the early hours of Sunday morning.
Guernsey Police said it happened sometime between 01:00 and 01:20, with one man suffering a head injury and going to the Emergency Department at the Princess Elizabeth Hospital for treatment.
Any witnesses who saw or heard anything are asked to call DC Ormrod or DC Simon in CID on 725111 or call Crimestoppers anonymously on 0800 555 111.
Pictured top: Candie Road, St Peter Port.