The young man attended a nightclub on the Bushmills Road on Wednesday, April 18.
In the early hours of the following morning, it was reported that the victim was assaulted as he left the premises.
Police are keen to speak to anyone who may have witnessed this incident. Anyone with information is asked to contact CID in Coleraine on 0845 600 8000 or anonymously to Crimestoppers on 0800 555 111.
