A serious crash investigation is underway to establish the cause of the crash.
Police said it was raining at the time of the accident but it was too early to say if the weather was a factor.
Truck driver Duane King was driving to Tokoroa when he came upon the crash.
He stopped his truck about 100m from the scene.
"It was bucketing down with rain just before it happened," Mr King said.
"I just saw the truck driver climb out of his cab and a white [vehicle] in the ditch.
"There was a ute as well with a log in front of it and people rallying around trying to help."
State Highway 30 was closed between Atiamuri and Rotorua until 7pm yesterday, while the investigation was carried out and the road was cleared, including removing a number of logs from the road.
No information about the dead man will be released until next of kin have been notified.
Less than an hour earlier, at 12.30pm, a car and small truck collided on State Highway 5 near Palmer Mill Rd, Wairakei.
That road was closed for a couple of hours while the wreckage and spilt oil were cleaned up.
The Taupo-based Greenlea Rescue Helicopter airlifted a 25-year-old woman with serious chest injuries to Rotorua Hospital.
