Waikato Hospital staff continue to face aggressive and abusive patients and visitors despite committing "significant funds" to the protection of staff and patients.
On Monday night staff made 20 calls to hospital security requesting help.
Waikato District Health Board spokeswoman Mary Anne Gill said most problems stemmed from drug and alcohol-fuelled abuse and violence in the hospital, which was "a major concern for Waikato DHB management".
That concern comes as a bill tightening laws around offending against frontline health workers passed its third and final reading in Parliament.
Justice Minister Judith Collins said the new law sent a clear message that offending against first responders would not be tolerated.
"Our police, prison officers, ambulance staff, paramedics, doctors, nurses and firefighters put their own lives at risk every day to rescue, save and protect their fellow New Zealanders," Collins said.
"They are the community's first line of defence against dangerous offenders and the first at the scene of serious accidents, fires and life-threatening situations."
Previously, there was no requirement for a judge to consider whether the victim was a first responder when sentencing an offender.
Gill said Waikato Hospital had introduced a greater security presence of up to nine staff, particularly in the emergency department on Thursday, Friday and Saturday nights.
"And we are currently trialling a de-escalation programme for front-line staff, including staff at Te Kuiti, Taumarunui, Tokoroa and Thames hospitals," she said.
St John central region has noted a marked improvement in the number of incidents involving frontline ambulance staff with two reported assaults this year following on from 17 in 2010 and seven last year.
Regional operations manager Grant Pennycook said every effort was made to ensure St John staff attending emergency incidents had up-to-date safety training, appropriate safety equipment and, where necessary, co-ordination with other emergency services.
"Our officers make allowances for patient and bystander emotions, which can run high at emergency incidents.
"However, assaults of any kind are unacceptable," he said.
Like the Waikato DHB, St John has a zero tolerance policy toward assaults on staff and Pennycook said he welcomed the new law.
Waikato DHB safety
Nine security staff working on Thursday, Friday and Saturday nights, particularly in emergency department.
Most safety and security issues caused by alcohol and drug abuse.
Waikato Hospital security received 20 calls from staff on Monday September 10, with six relating to aggressive or abusive patients or visitors.
Attacks on ambulance staff in central St John region have dropped.