The 47-year-old and two other Asian men aged, 30 and 33, were attacked by up to nine men in St Vincent Street in Glasgow city centre at about 3.20am on Sunday.
The men were walking along the street at its junction with Buchanan Street when they were attacked and verbally abused by the group of white men wearing polo tops and jeans.
The three victims were taken to the Royal Infirmary where the 30 and 33-year-old men were released after treatment. The 47-year-old man is recovering in hospital after undergoing surgery on his ear.
Detective Constable Stuart Nutt, of Glasgow City Centre CID, would like to speak to anyone who has information on what he described as a "vicious attack".