The accident happened just 1 km before Wat Thepkassatri at about 7:30pm after the driver had picked up two Russian couples from Phuket International Airport.
When volunteers from Phuket Kusontham Foundation arrived at the scene, they found a female buffalo that weighed more than one tonne lying on the side of the road with serious injuries including a broken left leg, broken ribs, and a bloody bruise on her hip.
Just 15 metres away, the van was stalled in the middle of the road with a broken front radiator.
According to the driver, 44-year-old Mr Amnat Jansuriwong, he was on his way to drop off the two Russian couples when he saw two buffaloes scurrying across the road. In the darkness, Mr Amnat could make out the animals but said he was unable to brake in time and smashed into one of the animals, which bounced off the van and into the side of the road.
The other buffalo ran away during the accident, Mr Amnat said.
Thalang Police attempted to find the owner of the animal but were unsuccessful. Police called in a butcher to get an estimated price on the animal before putting it down and carving it for sale.
The van was taken to Thalang Police Station.