People on Dunedin or Wakari Hospital premises threatening staff or others with knives are among violent incidents reported by staff.
This year there has been an average of 36 incidents a month involving abusive and violent patients and visitors, compared with last year's monthly average of 45.
In her report this month to the Southern District Health Board's hospitals' advisory committee, Otago general manager of diagnostic and support service Sonja Dillon said the number of incidents was of concern and would continue to be monitored.
Asked if the incidents occurred in any particular area, Ms Dillon said in an email response they occurred across the hospitals rather than in specific areas.
A variability in reported numbers between various services might just highlight areas that excelled in reporting incidents.
Among those reported were verbal or physical aggression, assaults, attempted assaults, intentional damage to hospital property, threatening staff or others with weapons, and concealing weapons, typically knives.
Incidents involving both patients and visitors have been reported, but details of which category was more troublesome were not available.
Ms Dillon said there could be contributing factors towards incidents, including a patient's clinical condition, alcohol, stress or fear.
The public could assist by understanding "we do expect that staff, patients and visitors will be treated with respect and that threatening and abusive behaviour is not acceptable".
The board had zero tolerance to aggressive behaviour.
In her report, Ms Dillon said the hospitals' security service was continuing to give presentations to staff, reminding them of the actions they should take if they felt threatened.
Guidelines were also being given around the appropriateness of requesting restraints.
