A 52-year-old Pinjarra man was killed in a motorcycle crash in Hacketts Gully, east of Kalamunda, on Monday afternoon.
Police say the man was riding a purple 2014 model Harley Davidson motorcycle when it came off the road and struck a tree about 12.30pm.
He was travelling in a north-easterly direction along Mundaring Weir Road, near Ashendon Road.
The man was conveyed by ambulance to St John of God Midland Hospital after suffering life-threatening injuries, but died shortly after.
Major Crash officers would like to speak to anyone or saw the crash or the Harley Davidson motorcycle prior to the crash.
Anyone with any information is urged to call Crime Stoppers on 1800 333 000 or report online at www.crimestopperswa.com.au