About 4.35pm, a white Citroen hatchback and a blue Nissan Dualis station wagon, both travelling along Broomehill-Gnowangerup Road collided.
The driver of the Citroen, a 45-year-old man, sustained critical injuries and died at the scene.
The driver of the Nissan, a 26-year-old man, sustained serious injuries and was airlifted to Royal Perth Hospital.
Major Crash investigators are urging anyone who saw or has information relating to this crash, or who saw either vehicle travelling in the area prior to the crash, to contact Crime Stoppers on 1800 333 000 or online at www.crimestopperswa.com.au .
Dash-cam, or mobile phone vision relating to this crash, can be uploaded directly to investigators via the link: https://wapf.au.evidence.com/axon/community-request/public/pallinupcrash
If you or anyone you know has been affected by a road crash, contact Road Trauma Support WA on 1300 004 814.