Police will investigate to determine what caused an accident after a man died in a fatal collision near Nowra yesterday.

About 7.30am yesterday, a car and heavy vehicle towing a dog trailer collided on Braidwood Road at Yerriyong.

The truck left the road and rolled about 50 metres into bushland before coming to rest on its side.

The 65-year-old truck driver was airlifted to St George Hospital in a critical condition while the deceased driver of the car is yet to be identified.

A report will be prepared for the Coroner.