Traffic Enforcement Group officers are investigating a serious crash which occurred on Kwinana Freeway, Karnup early Friday morning.
About 1am, the male rider of a blue Honda motorcycle was travelling north near Karnup Road when he collided with a deer that was on the road.
The rider suffered serious injuries (broken arm, leg and severe road rash) and was conveyed to Royal Perth Hospital.
The deer was fatally injured.
Police are investigating whether speed was a factor in the crash
The 31-year-man from Kiara will be charged with no authority to drive and will appear in court at a later date.