Two people have been trapped in vehicles and are being sent to Royal Perth Hospital via the RAC rescue helicopter following a crash in Muchea on Wednesday morning.
The head-on crash involving two vehicles was reported to emergency services around 8am on Brand Highway, 10 kilometres north of Muchea.
Police said two people were reported to be trapped.
A patient has already been sent to hospital via helicopter as career and volunteer Fire and Rescue Service firefighters work to free a second person who is trapped.
That person will also be transported to Royal Perth Hospital later this morning.
Brand Highway is currently closed at Chittering Street.