Police have appealed for witnesses after a man was glassed in the face outside a St Kilda cafe on Thursday.

Investigators were told that the 27-year-old victim from Essendon and his friends were sitting outside an Acland Street cafe about 1.30am when they were approached by two women and a man who had just walked out of a nearby nightclub.

The two women stopped and spoke to the group, before the man they were with grabbed a glass off a table and struck the victim in the face, a police spokeswoman said.

The victim was treated by paramedics at the scene and he was taken to the Epworth Hospital.

The offender then walked towards Barkly Street and a fight broke out when two of the victim's friends caught up with him. He then broke free and ran off.

The offender spoke with a Scottish accent and is described as of Caucasian appearance and about 180cms tall, with medium build and short dark hair.

Anyone with information is asked to phone Crime Stoppers on 1800 333 000.