The incident happened around 3.25am in the cobbled area in the centre of George Street and left a 26-year-old man needing hospital treatment for a head injury.
Officers are now appealing for anyone who was in the area at the time or who has information that can assist them with their inquiries to please get in touch.
The man was crossing George St with two friends when a white Audi A3 was turning in the road.
An argument occurred between the man and the occupants of the car which led to the occupants getting out of the car and assaulting him.
The suspects are described as men in their 20’s, two of them being black and one white. There was also a blond-haired white woman in her 20’s with the group.
Detective Sergeant Kevin Tait of Corstorphine CID said: “I’d ask anyone who was in the area or who has information that can help us to trace these individuals to please get in contact.
“The incident has left a young man requiring hospital treatment for a significant head injury and we are keen to identify the individuals responsible.”
Anyone with information is asked to contact police on 101 or anonymously via Crimestoppers on 0800 555 111.