Rescuers had to use night vision goggles and a winch to reach a man who had rolled his quad bike.
The Auckland rescue helicopter was called to the crash site near Taumaranui late last night.
The crash happened in an area of steep terrain, which meant rescuers had to use specialist gear to get to him.
The man, in his 30s, suffered multiple injuries and was flown to Auckland Hospital in a serious condition.
Earlier yesterday, a man in his 50s had to be flown to hospital after a collision with a woman riding a farm bike.
The man, who had been on a road bike, was sent into a culvert and sustained multiple injuries.
He was airlifted from the site at Hikutaia, north of Paeroa, to Waikato Hospital in a serious condition.