Police are appealing for witnesses following an assault outside the Blue Bell pub in Bell Hill, Rothwell on Monday afternoon.
The victim was in his car and was sounding the horn after being blocked in by another vehicle. A man, who was not the owner of the second car, came out of the pub and told the victim to stop beeping the horn.
The man lent into the car window and punched the victim several times in the face. He then opened the door, dragged the victim out of the car and continued to assault him before going back into the pub.
The offender is described as white, about 5ft 11in, with a stocky build and his 30s. He had short brown hair and slight stubble, and was wearing dark jeans and a blue T-shirt. He had tattoos on both arms.
The incident happened between 5.20pm and 5.30pm.
Witnesses, or anyone with information, are asked to call Northamptonshire Police on 101. Alternatively, they can call the independent charity Crimestoppers anonymously on 0800 555 111.