Police are investigating the circumstances surrounding a fatal collision in Great Western on Friday morning.

It is understood two vehicles collided on the Western Highway about 7.50am.

Sadly, the driver of one of the vehicles was pronounced deceased at the scene. They were the sole occupant of the vehicle and are yet to be formally identified.

The male driver of a white Holden Vectra has been taken to hospital with non-life-threatening injuries and is assisting police with their enquiries.

Police are continuing to investigate the exact cause of the collision and are appealing for information from anyone who saw the white Holden Vectra before the incident.

Part of the Western Highway was closed well into the afternoon while Major Collision Investigation Unit detectives processed the scene.

Anyone who witnessed the collision, with dash cam footage or further information is urged to call Crime Stoppers on 1800 333 000 or submit a confidential report at www.crimestoppersvic.com.au.