The accident happened at 7.30am today on the busy A736 Irvine to Barrhead Road in Kilwinning, Ayrshire.
Police have confirmed that the driver of the motorcycle was inured and has been airlifted to the Southern General Hospital in Glasgow.
The van driver was not hurt.
The road has been closed at its junction with Torranyard Caravan Park and Sourley St and local diversions are in place.
A Police Scotland spokesman said: "Officers are still on the scene. There are no further updates at this time."