Police are investigating a hit and run crash in Beaconsfield which left a motorcyclist seriously injured.

It happened about 7pm last night at the intersection of South and Solomon Streets.

Police say a blue Yamaha bike collided with an unknown vehicle which failed to stop and fled the scene.

The rider a man in his 40s, was taken to Fiona Stanley Hospital with serious but non-life threatening injuries.

Anyone with information or dash-cam vision is urged to contact Crime Stoppers on 1800 333 000.