Senior Constable Lox Kellas, of Portobello, said one southbound car and two northbound cars were in a collision about 4.30pm.
The sole occupant of the southbound car received serious leg injuries and it took emergency service workers about an hour to free him from the vehicle.
He was flown to Dunedin Hospital by the Otago Regional Rescue Helicopter.
The driver of the first northbound car, which crashed off the road and came to rest on rocks, received a broken elbow and was taken to hospital in an ambulance.
His passenger, a young girl, was not injured.
The driver and passenger of the third vehicle were not seriously injured, Snr Const Kellas said.
Three ambulances and two fire appliances attended, as did the serious crash unit.
Investigations are continuing.
