Police are appealing for witnesses to come forward after a man in his 40s was assaulted in Wimborne sometime between 11.30am and midnight on Saturday 21 January.
The man left the Cricketers Arms on Park Lane and walked toward Crown Mead when he was approached by a group of men in their late teens near the steps for Wimborne Library.
It is believed one of the men, who was wearing a red jacket, pushed the victim from behind and kicked him in the chest, causing him to fall over and hit his head on the ground. He was helped up by an unknown person, before walking home.
The victim began to feel unwell on Sunday evening, 22 January, and attended hospital where he was found to have a fractured skull and bleed on the brain.
His injuries are not believed to be life-threatening.
The incident was reported to the police on 23 January.
Detective Constable Laura McQueen, of Bournemouth CID, said: “This was an unprovoked attack on a man, who was making his way home after an evening out, that has left the victim with serious life-changing injuries.
“We are making a number of enquiries to identify the offender and I would ask that anyone who may have witnessed the incident or has information about the person responsible to come forward.
“I am also appealing directly to the person responsible or his friends to do the right thing and contact police.”