The stop-work action by nurses and midwives on Tuesday will affect elective surgery and cause delays for some patients, while support for life-saving care will not be impacted.
Health Minister Ryan Park said officials had sought to contact patients with surgery scheduled to make alternative arrangements due to the industrial action.
"I acknowledge the dispute between the government and the association has a way to go," he said in a statement on Monday.
The NSW Nurses and Midwives Association action will start at 7am in the union's second major stop-work action since Labor came to power in March 2023.
The strike is part of a union push for a 15 per cent one-year pay hike for members, a demand Premier Chris Minns has said is unaffordable.
"I just can't agree to the 15 per cent one year increase in pay," Mr Minns said on Monday.
All NSW public sector workers, including nurses, have been offered a three-year 10.5 per cent pay increase factoring in a mandatory rise in superannuation payments.
The union says Labor has failed to express a willingness to move its position after months of talks, prompting the strike.
Industrial Relations Commission president Ingmar Taylor has not yet examined the union's argument for pay rises, but recommended an interim deal and four weeks of "intensive discussions" in a bid to broker a deal.
The interim offer involved a three per cent wage increase with back-pay if nurses agreed to halt industrial action.
"The Industrial Relations Commission has set out a very reasonable recommendation that would see nurses receive an interim pay rise back-paid to 1 July, while at the same time sparing patients from impact to their care," Mr Park said.
NSW Liberals leader Mark Speakman said the government needed to do everything it could to make sure the strike did not compromise patient safety.
"It's also incumbent from the nurses union to cooperate to the same extent," he said.
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