Police were called just after 1pm this lunchtime to a van in collision with a motorcycle on the A3 near the junction with Coombe Lane.
The rider of the motorcycle, a man aged in his 20s, was taken to hospital.
He has sustained serious injuries, but his condition is not believed to be life-threatening.
There has been no arrest.
Any witnesses yet to speak with police are asked to call 101, ref 3684/09oct.
The A3 was closed in both directions but has since reopened.
