The crash, involving two trucks and cars, occurred 1km north of Porteous Rd on the Kilmog hill.
Fairfax media are reporting that one man, in his 70s, was flown to Dunedin Hospital with moderate injuries, while a man and a woman, both with minor injuries, were taken to hospital via ambulance.
It is understood one of the trucks involved is a truck and trailer transporting cattle.
The northbound lane was blocked for a time and there were delays for motorists, but the New Zealand Transport Agency advises that the road is now clear.