Qld Ambulance Service said several stable patients were assessed for smoke inhalation but no transport was required.

Roadhouse owner and Diamantina Shire Mayor Robbie Dare said the roof had collapsed and 95 percent of the building was destroyed in the fire which started around 3.30am Tuesday morning.

"The person in the caravan park (across the road) had seen it in the corner of the building," Cr Dare said.

"Looked like it started in the top of one of our drop-in cold rooms."

Local Rural Fire Service volunteers were quick on the scene and Cr Dare said the fire was still only in that area at the time but it took off quickly to engulf the rest of the building.

"The firies did a fantastic job," he said.

"Virtually half the town was there within 20 minutes."

Cr Dare said the fire may be related to the electric motor in the cold room.

"That's all that's there," he said.

Cr Dare said the accommodation area of the roadhouse was still standing but the main building containing the shop and restaurant were destroyed.

"We are going to have to look at an alternative venue to cook for the motel rooms," he said.

"Police are flying in this morning and insurance is flying in, we're not allowed in the building, there's a lot of product that's salvageable in the cold rooms and freezer rooms."

The fire is a blow to the small town of 150 people with the roadhouse being the main meeting place in Bedourie and the only place which sold fuel and groceries.

The nearest fuel is Birdsville, 200km south or Boulia 200km north.

READ ALSO: Nardoo sells for $35 million

While you are here, subscribe to our weekly email delivered to your inbox every Tuesday and Friday.