A 20-year-old woman was airlifted to Royal Perth Hospital with serious injuries after crashing into a tree in Wandering on Thursday.

The crash happened at around 6.44am at the junction of Wandering-Pingelly and Deans Road in Wandering, about 50km north-west of Narrogin.

The woman was initially trapped but was freed by fire and rescue crews.

A spokesman for the Department of Fire and Emergency Services said the woman was flown to RPH by the RAC rescue helicopter at around 9.10am.

The woman has serious but not critical or life-threatening injuries.