The exact location of the collision is at the entrance to Wharfedale Grange Farm on the A61 near to the village of Harewood.
The collision occurred at around 9.25 this morning (Thursday 21 July 2011) and involved a green Ford Ka and a grey Kawasaki motorcycle.
Both vehicles were travelling in the same direction towards Leeds.
The man riding the motorcycle was airlifted to Leeds General Infirmary with multiple injuries.
The woman driver of the Ford Ka was treated at the scene by paramedics, she was not admitted to hospital.
Police are appealing for anyone who witnessed the collision or the manner of driving of either vehicle prior to the crash, to contact them.
The road is currently closed and is expected to remain closed for the next two hours.