In only the next decade, the number of stroke sufferers could balloon by 40 per cent.
If further reductions in stroke incidence couldn't be achieved, the number of sufferers could rise from 7231 in 2015 to 10,112 in 2028.
This increase - forecast in a study published in the New Zealand Medical Journal today - would come as a result due to our ageing and growing population.
But the figure still came as a surprise to the researcher who led the work.
"We knew it would go up but didn't expect the increase to be quite this high," said Associate Professor Anna Ranta, who heads the University of Otago's Department of Medicine in Wellington.
"The large increase emphasises that our New Zealand health sector needs to implement effective stroke prevention programmes and stroke intervention strategies to minimise the impact on both human suffering and healthcare expenditure."
In New Zealand, it had been estimated up to 9000 people had a stroke each year, and 50,000 people lived with the consequences.
The annual cost has been estimated to be $700m.
Ranta said the new study aimed to project stroke volumes over the next 10 years to help with health sector planning.
"Because these figures are growing due to our population growing, it is imperative that the health sector plans ahead and implements effective and appropriate prevention and post-stroke intervention strategies to manage the rise in stroke burden."
Vivian said while stroke treatment had improved greatly and was now more widely available, prevention remained better than cure.
"The Government must do more and spend more, to help all New Zealanders reduce their stroke risk," he said.
"Anyone can have a stroke, so this vital health issue affects everyone.
"Three-quarters of strokes can be avoided by following a healthy lifestyle and getting regular blood pressure checks."
Meanwhile, he urged all Kiwis to learn FAST, which taught people to recognise the most common symptoms of stroke - facial drooping, arm weakness, speech difficulties - and dial 111 immediately.