Arriving at the scene, near the Thavorn Beach Village resort, Kamala police and Ruamjai Katanyu Foundation rescue workers found a large tree lying across the road and across the cab of the pick-up.
The passenger, later identified as Supong Phoomcharoen, 35, had already been taken by local people to hospital, suffering from neck and leg injuries.
The driver of the pick-up, Supachai Suksawatdee, 30, who was uninjured, told police that he and Mr Supong were going to Kamala from Chalong through very heavy rain when the tree fell on them.