One man has died at the two truck crash on Old Coast Road in Myalup this afternoon.
Another man has been airlifted to Perth and the extent of his injuries is unknown.
Firefighters, police and the RAC Rescue chopper attended the scene of a crash.
The crash happened on the northbound lanes of Old Coast Road just south of Forestry Road at about 2pm this afternoon.
The northbound lanes are still closed and are likely to stay that way until at least 10pm.