More than a third of the country's public lavatories have no soap and some even lack running water - a finding public health experts say could harm the country's reputation as a tourist destination.
The Otago University study, published in the New Zealand Medical Journal, is the first multi-region survey of public loos and the latest to highlight poor attitudes to hand hygiene.
Researchers surveyed 150 council-run public toilets in seven cities, 30 towns and 18 different local authority regions in the lower North Island.
They found 39.3 per cent of toilets had no soap and 4 per cent had no running water, with rural and minor urban areas worse off than cities.
Return visits to 51 of the facilities revealed no overall improvements in soap and water availability. Other issues included a lack of signage, doors that did not shut properly, a lack of cleanliness and automatic flush systems that did not work.