Emergency services were called to an accident involving a car and a motorbike in Chichester this morning (Tuesday).
Sussex Police confirmed officers were called to Northgate at 7.46am.
In a statement at 9am, a police spokesman said: "The extent of injuries is unknown.
"The ambulance service has just arrived on scene."
South East Coast Ambulance Service confirmed the motorcyclist was assessed and treated for arm and leg injuries at the scene, before being taken to St Richard’s Hospital.
Heavy traffic was reported on A286 Northgate at Alderman's Walk, stretching back to Westgate.