A man was assaulted while walking through Corby town centre on Sunday, September 10, between 8pm and 8.30pm.
As the man and a friend passed the Corby Candle pub, a group of young people began to follow them.
The two men then walked up Montrose Street and, as they reached the junction with Argyll Street, the victim was kicked in the back causing him to fall.
While on the ground, he was kicked again in the head.
The suspects are described as young males and one of them wore a grey hooded top.
Witnesses, or anyone with information, is asked to contact Northamptonshire Police on 101 or Crimestoppers anonymously on 0800 555111.