More than 9000 New Zealand nurses have registered to work in Australia in the past 10 months - about 12 percent of the active workforce.
The rate of nurses expressing interest is growing, despite a boost in pay last year.
Any nurse wanting to work in Australia must first get a registration with the Australian Health Practitioner Regulation Agency (Ahpra).
The latest figures show an average of 900 a month had signed up in the 10 months until January. In April last year, the average was 625 a month over eight months.
Ahpra did not track how many nurses actually went on to get jobs.
A scan of nursing ads on job website Seek showed some offering NZ$117 an hour for contract work in very remote areas.
Another agency was offering free trans-Tasman travel for locum work of eight weeks or more.
An ad for a permanent role at a rural aged care home offers $17,000 in meal and entertainment allowance and a $7500 sign up bonus over four years.
Kerri Nuku, the kaiwhakahaere of the union the Nurses' Organisation, said she knew of many nurses who were going to work in Australia, often on short-term locum work.
"They are also going because it does have a different quality of work and different opportunities and professional development and training so there are a number of factors that are making nursing in Australia seem slightly better than here in Aotearoa," she said.
Base pay rates for Te Whatu Ora nurses had increased last year to be similar to Australian hospital rates.
However, private health clinics often paid higher rates and short term contracts were higher, and nurses working in GP or iwi clinics here were still paid less than their Te Whatu Ora counterparts.
"More of the nurses in primary care in New Zealand are chosing to go and work over in Australia because they offer better salaries which the primary care sector just can't compete with," Nuku said.
The Nursing Council of New Zealand said it gave out 9511 verifications of good standing to Ahpra for New Zealand registered nurses last year, with 85 percent of them for overseas-trained nurses.
Nuku said it was possible some of those international nurses would get registration here but go straight to work in Australia without setting foot in New Zealand, and more information was needed to find out how often that was happening.
The Nursing Council did not keep data on it.
The number of registered nurses in New Zealand overall grew by 9357 last year to 77,634, with an estimated four to five percent of them not working at any given time.
Health Minister Shane Reti said more work needed to be done to see how many of those registering in Australia were actually taking up work there.
New Zealand had had a huge boost in overseas qualified nurses arriving in the last quarter of 2023, and more information was needed about what was happening to them, he said.
"Ideally we would want to keep them here but I do understand some transition. Some may not even touch base on New Zealand soil, they may register from offshore and then transition straight to Australia."
New Zealand was part of a global shortage of nurses, and there had always been movement between Australia and New Zealand, he said.