A 23-year-old was rushed to hospital after being attacked and left unconscious while on a night out with friends.
The victim had just emerged from a taxi when he was approached by another man and attacked.
He collapsed to the ground and struck his head on a kerb rendering him unconscious.
The victim was taken to hospital at the Royal Infirmary to be treated for head injuries.
The attack took place in the early hours of Tuesday morning, at York Place in Edinburgh.
Police are hunting for a man described as mixed race, around 20-years-old, around 5ft 8 ins tall, with short dark hair and was wearing a pink stripy shirt and dark navy jeans.
They added that the suspect could be Turkish, may have had a mole on his face, and is believed to have spoken with a north east of England accent.
A spokesman for Lothian and Borders Police said: “Thankfully, the man who was assaulted was not more seriously injured.
“However, we are treating this incident seriously.
“Anyone who was in York Place at the time, and witnessed the assault, should contact police immediately.
“Similarly, anyone who has information that can assist our enquiries is also asked to get in touch.”