Police are investigating a fatal collision involving a motorcycle on the A350 near Shaftesbury.
It happened south of the junction to the village of Motcombe, on the Wiltshire and Dorset border, at about 2.35pm on Saturday.
Wiltshire Police said "for reasons currently unknown" the motorbike, travelling south, crossed the carriageway and collided with an Audi Q5.
The motorcyclist, a man in his 30s from Dorset, died at the scene.
The force said his next of kin had been informed their thoughts were with them at this difficult time.
The road was closed for investigations until 10pm.