The family of a 29-year-old Corkman who has been left fighting for his life at Royal Prince Alfred Hospital after an assault in Randwick on Sunday night, are currently en rout to Sydney from Ireland to be at his bedside.

Paddy Fox underwent emergency surgery after a serious assault in Randwick on Sunday night outside the Royal Hotel.

Police have arrested and charged a 19-year-old man over the attack, but he has been released on bail to appear at Waverley Local Court on April 13.

The assault allegedly occurred at the hotel in Perouse Road around 8pm, in which Mr Fox, who has an address in Coogee, fell back and struck his head on the ground, according to police.

He was admitted to the Intensive Care Unit of the Royal Prince Alfred Hospital with serious head and brain injuries, and underwent emergency surgery.

On Monday, detectives from the Eastern Beaches Local Area Command attended an address in Cook Street, Randwick, and arrested the teenager.

He was taken to the Maroubra Police Station where he was charged with recklessly inflict grievous bodily harm.

The assault comes just months after the death of Gearóid Walsh who died after an altercation with another man in Coogee in October.

by Aaron Dunne