Nurses and midwives walked off the job for four hours at Lake Macquarie Private Hospital on Monday to rally for better pay and conditions.
The four-hour strike sought to highlight the "unacceptable pay and conditions offer" from the hospital's owner Ramsay Health Care in a new enterprise agreement.
Members of the NSW Nurses and Midwives' Association (NSWNMA) rallied on the Pacific Highway, opposite the hospital at Gateshead.
The protected action included bans on working overtime and led the hospital to cancel "several patients' surgeries".
Ramsay has offered the workers an 11 per cent pay rise over three years, but the workers are seeking 18 per cent and improved conditions for parental and personal leave.
It's the first time members have taken protected industrial action against Ramsay in NSW, after 81 per cent of nurses and midwives rejected its offer.
The union urged Ramsay to "put staff and patients before profits", highlighting that the company's global net profit last year was $365.5 million.
The union's branch president for the hospital, Melanie Crimmins, said negotiations with Ramsay had been occurring for 13 months.
"They're still not budging on pay and conditions," Miss Crimmins said.
"We didn't really want to take this action. Our hand has been forced."
Branch member Leanne Molenaar said "Ramsay is not respecting us".
"They're undervaluing us as nurses," Mrs Molenaar said.
"We would like the same respect from Ramsay that we give to their patients.
"Without the nurses, Ramsay don't have a hospital. If they could come to the negotiating table, that would be wonderful."
A Ramsay Health Care spokesperson said its proposal was "competitive with public and private sector wages" and had "more flexibility, greater control and other benefits".
It said negotiating fair wages and conditions required balancing appreciation for nurses and midwives "with the long-term sustainability of the company".
Negotiations were occurring "at a time when the private hospital industry is facing significant financial challenges".
Miss Crimmins said the hospital was "currently using a lot of agency staff in our hospitals and there's a lot of overtime".
"We're overworked, we need more nurses. I've worked at this hospital for 20 years.
"I've never seen it as bad as it is at the moment. We have agency staff on every single shift."
Miss Crimmins said the cost of living was hitting people hard.
"I'm a single parent of a child with special needs," she said.
"You can't run a household without overtime or working penalties. That's not sustainable."
Mrs Molenaar said she had "been a nurse for 40 years and I've never before felt the need to strike".
The workers are also demanding that Ramsay commits to safe staffing ratios in its NSW hospitals.
Branch secretary Bronwyn Wratten said "nurses and wives are fed up with their working conditions".
"We want to provide quality care for our patients and they're really not allowing us to do that. There's no minimum safe staffing," Mrs Wratten said.
She said the pay rise was needed to "be able to pay rent, mortgages and bills".
"Everyone is struggling," she said.
