Waitati Volunteer Fire Brigade Deputy Chief Fire Officer Lindsay Scott said crews from the Waitati and Dunedin City stations were called to the nursery in Harvey St, Waitati, about 11.45am.
The nursery is in the same street as the fire station in the seaside settlement, which is about 20km north of Dunedin.
When the first crew arrived, the front of the van was engulfed in flames, Mr Scott said.
The burning van was empty as its occupants were inside the nursery, he said.
The occupants were New Zealanders visiting Dunedin, he said.
The fire was believed to have been caused by an "electrical fault" and was not being treated as suspicious.
"It was just bad luck."
He believed the "expensive-looking camper van" was damaged beyond repair.
The Waitati crew was called back to the nursery about 1.45pm when someone mistook steam rising from the van for smoke.
