Te Whatu Ora Waitaha says new, additional security guards in Christchurch Hospital's Emergency Department helped to swiftly contain a gang fight.
Police received a report about 8.15pm on Wednesday that four Mongrel Mob gang members or associates had an altercation in the waiting room.
One person was assaulted and one was arrested.
"No patients or staff were in danger, and the response by our security team was immediate and commendable," said Te Whatu Ora Waitaha Health Canterbury's interim group director of operations Jo Gibbs.
She said the first guard on the scene "was only metres away" when the fight broke out and took five on-site guards to bring it under control before police arrived, Gibbs said.
"The quick actions of the security team, bolstered by the new additional guards in ED meant that the incident was swiftly contained in a matter of minutes," she said.
"Te Whatu Ora does not accept violence or abuse in any of our facilities."
The usual process when an assault happened was to call police and they arrived quickly when called, Gibbs said.
The government announced a $5.7 million boost to ED security December, which aimed to employ an extra 200 people in the short term.
Health Minister Dr Shane Reti said it was in response to increasing violence and abuse reported in EDs across the country.
1179 assaults were reported by Te Whatu Ora Health New Zealand in 2021, rising to 2459 in 2022, he said.
Another 1267 were reported in just the first three months of 2023 which was a concerning trend, Reti said at the time of the announcement.
Many of the roles were part time, amounting to 93 full-time equivalent positions.
It was only due to be funded to the end of February at the latest, but the government was also investigating a longer-term solution, the Health Minister said.