A teenager has had emergency surgery in Whangarei Hospital after his throat was slashed with a knife, police say.

The 18-year-old was involved in a fight with two other men in the central business district around 2.10am on Saturday.

Detective Sergeant Shane Pilmer said the young man was expected to make a full recovery after the surgery.

A 17-year-old male had been arrested and would appear in Whangarei District Court on Monday.

Det Sgt Pilmer said police were appealing for any witnesses to the incident.

NZ Newswire