Three teenagers have been charged over the glassing of a 16-year-old boy at Dudley just after midnight on New Year's Day.
Lake Macquarie Police said the victim suffered "serious injuries in an alleged assault".
The victim is in a critical condition and induced coma, a police statement said.
The incident happened at about 12.10am in Ocean Street.
"Officers attached to Lake Macquarie Police District attended and were told a 16-year-old boy had been struck to the head with a glass bottle, suffering serious lacerations," the police statement said.
"He was treated at the scene by NSW Ambulance paramedics and taken to John Hunter Hospital in a critical condition, where he remains in an induced coma."
Police established a crime scene and began "inquiries into the circumstances surrounding the incident".
Two males, aged 17 and 16, were arrested nearby and taken to Belmont Police Station.
Another 17-year-old male was arrested at the station a short time later.
All three males have been charged with reckless grievous bodily harm in company and reckless wounding in company. They were refused bail to appear in children's court on Sunday.
A NSW Ambulance statement said paramedics were called to the incident and "treated a teenage boy for a head injury".
Anyone with information about this incident is urged to contact Crime Stoppers on 1800 333 000 or nsw.crimestoppers.com.au.
