Police are investigating following a serious head-on car crash in Treeby on Wednesday night.
A Holden Commodore utility lost control on Warton Road near Ackworth Road, crossing a median strip and colliding head-on with a Toyota Landcruiser travelling in the opposite direction.
The 30-year-old male Holden driver suffered life-threatening injuries and was taken to Royal Perth Hospital by St John Ambulance.
He remains in a serious by stable condition.
Meanwhile, the 24-year-old driver and 26-year-old passenger of the Toyota sustained minor injuries and were treated at Armadale Hospital.
Police are investigating the incident and will determine whether alcohol and speed were factors in the crash.
Anyone with information is asked to call Crime Stoppers on 1800 333 000, or make a report online at www.crimestopperswa.com.au