Figures obtained by Newshub show 95 staff or visitor cars were stolen or broken into at Middlemore Hospital in the space of a year - the equivalent of about 8 each month.
The car parks at Middlemore along with those at Whangarei Hospital rank the highest in the country for vehicle crime.
Nurses say they "work in fear" and some are "giving up" reporting incidents to management - but authorities insist they are taking action.
Photos provided to Newshub show the smashed-up remains of a car after an offender tried to hot-wire it at Whangarei Hospital earlier this year.
Another image shows a young offender fleeing the scene.
Car break-ins are not unusual according to New Zealand Nurses Organisation Whangarei representative and registered nurse Bridget Firth.
"You just want to go to work and you want to feel safe, and you want to be able to leave your 12-hour nightshift and go home," Firth explained. "You don't want to have to ring insurance companies, you don't want to have to ring for a ride."
Issues with security have become so regular that staff have even been warning one another on social media as events unfold.
"One of our colleagues was chased by someone (a guy wearing a black hoodie tonight). She managed to get away to her car and get away but it's not worth the risk", a post from a staff member read.
Firth said staff feel "vulnerable" and one of her colleagues had her car stolen from hospital grounds twice.
"You're taking care of these peoples whanau and loved ones and that's what they do in return," she said.
Official information shows in the 12 months to the end of April this year, 39 vehicles at Whangarei Hospital were reported as being stolen, broken into or tampered with.
Hospital management said they're aware of the problems and take it seriously.
"It definitely is a priority, so we've put in place a number of initiatives," said Te Whatu Ora's Northland Clinical Support Services general manager Chris McLellan.
The new initiatives include adding two new cameras, repositioning existing ones, modifying the times security do patrols - to match peaks in crime, and utilising community patrol services.
Additionally, there are also "plans to increase and change lighting".
However, Firth said she'd like to see fencing installed around the car parks. That's not currently part of the plan but management claims vehicle theft has now dropped to about one incident per month.
"We have noticed in the past spikes, but over the past three to four months it's been really positive in terms of the lowering of offences committed against staff," McLellan said.
At Auckland's Middlemore Hospital, the figures are even worse, with 37 incidents reported by staff and 58 incidents reported by patients and visitors in 12 months to April 2023.
Those numbers don't include the daylight theft of a pregnant woman's car late last year.
The New Zealand Nurses Organisation (NZNO) said some workers no longer bother informing Te Whatu Ora management of car break-ins.
"They are giving up, they're not reporting and I don't believe that it really reflects what's happening out there," NZNO President Anne Daniels said. "Second of all, this is a real health and safety issue."
"They have to actually live in fear going to and from work and this is just not okay," she said.
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Te Whatu Ora for Counties Manukau said it's trying to minimise crime.
A spokesperson told Newshub guards have increased their presence in high-risk areas at Middlemore Hospital, lighting and fencing have been improved and what they call a "security command centre" with better CCTV is being constructed.
Daniels said there's a legal requirement to provide a safe environment for staff - and she believes Te Whatu Ora has failed to meet its obligations.
"Te Whatu Ora says it values their staff, they need to actually walk the talk."
