The death comes less than a week after emergency services were called to the crash on Maraetai Drive, in Auckland, last Wednesday.
Authorities said one vehicle was involved and that two people had been critically injured.
One was airlifted by the Auckland Westpac Rescue Helicopter to Auckland City Hospital. The other was taken by ambulance to Middlemore Hospital.
The serious crash closed Maraetai Drive for some time as emergency services worked at the scene.
The second person in hospital is said to be in a stable condition in hospital, police said.
The circumstances of the incident are not yet known. Police said the investigation into the crash remains ongoing.