Police are investigating a collision at the intersection of Lakes Road and Waldron Boulevard in Greenfields on Thursday night.
About 9.05pm, a Holden Rodeo and a white Nissan sedan collided, causing significant damage to both cars.
Mandurah Police and St John Ambulance officers attended the scene.
A man, in his 20s, was taken to Peel Health Campus for treatment on an injury to his right shoulder.