The 35-year-old was on the footpath at Barrie Road, near the junction with Kenilworth Road, when the attack happened shortly before 11pm on Thursday.
Police believe he may have been attacked with a weapon. He was taken to Monklands Hospital for treatment to a serious injury to his face and has since been released.
Constable Scott Brown from Hamilton Police Station said: “This incident left a man needing treatment in hospital, and we are keen to hear from anyone who was in the area at the time.
“Anyone with dashcam footage, or who saw anything on Thursday evening, is asked to call 101 quoting reference number 3813 of 7 October 21.”