Police say the B train truck rolled at the bottom of Cluden Hill on the Lindis Pass-Taras Road (State Highway 8) at 5.20am.
The man had moderate injuries but was not trapped in the cab.
The driver was taken to Dunstan Hospital by St John ambulance.
A spokesman from Fire and Emergency New Zealand said three crews from Cromwell, Tarras and Luggate attended.
The road was cleared by 6.20am.
The truck was a Summerland vehicle and comes after the transport company has come under scrutiny for a number of incidents since December 2017 when a Summerland truck-and-trailer unit lost control at the bottom of Pine Hill Rd before rolling on to its side and coming to a halt near the Dunedin Botanic Garden.
It was fined over that crash.
Since then there have been a number of other incidents, including a truck carrying dangerous goods running off SH8 in January leaving the driver with moderate injuries.
In February a truck-and-trailer unit carrying tins of milk powder caught fire in South Canterbury. The trailer was completely destroyed, but the driver managed to save the truck.
