James Beaumont, formerly of Launceston, had been walking out of a pub in Kalgoorlie, where he has lived for the past year, when he was allegedly punched in the back of the head.

The blow caused him to fall straight on to his face, leaving the 23-year-old with a broken jaw in three places, broken nose, a fractured eye socket, bruising to the brain and a few less teeth.

He was transported to the closest hospital before later being flown to the Royal Perth Hospital, where he is recovering.

Mr Beaumont and his friends have pleaded to others via social media to ``use your brain and not your fists'' when out drinking.

``I might not be the biggest saint but does anyone deserve to be king-hit from behind?'' Mr Beaumont posted on Facebook on Monday.

Friend Andrew Hendry, of Launceston, said he had never realised how much a coward punch could affect someone until the past weekend and luckily his friend would recover.

``But for others it could be much worse,'' he said.

``Until it's your best mate you don't realise and I don't want this to happen to someone else's best mate.

``We've got to get the word out and the community's got to be concerned for these kind of incidents.''

Mr Hendry said if someone was willing to king-hit someone in the back of the head, they should serve jail time.

``Until the court appropriately deals with people who king-hit, it's just going to keep happening,'' he said.

Mr Hendry urged Launceston pubs and clubs to get behind the one punch campaign that other state's had implemented and start advertising about what a ``coward punch'' could really do.