In the past two years there have been more serious mistakes made by ambulance officers, including some which resulted in patients' deaths, than in the previous seven years combined.
The figures obtained by RNZ News show a huge surge in the numbers of mishaps.
A person having a heart attack dying after an ambulance officer inserted a tube to help them breathe into their neck tissue rather than their windpipe.
In another case, a person died after their medical alarm was activated but no ambulance was sent because the dispatcher confused the emergency with another incident.
In 2015 Hamilton woman Vickie Thompson fainted and was taken in a stretcher to hospital, where she was dropped head first on to concrete.
The incidents have come to light in Health Ministry records obtained by RNZ News under the Official Information Act.
Lynette Blacklaws, First Union's co-ordinator for ambulance workers, says the service is underfunded and the staff are under pressure.
She told Morning Report the figures are alarming, but not totally surprising.