A 17-year-old boy was airlifted to hospital in Bristol after crashing into a tractor in Calne.
The casualty was riding a bicycle along a single track road at Hazeland from the direction of Studley towards Bremhill at around 12pm.
As the cyclist, from Chippenham, negotiated a left hand bend, he collided with a tractor travelling in the opposite direction.
He was airlifted to Southmead Hospital by Dorset and Somerset Air Ambulance with suspected head and shoulder injuries.
The driver of the tractor was not injured.
Wiltshire Police is asking anyone who witnessed the incident to call 101 and quote log number 119 of June 27.
Don't miss out on breaking local 999 news - follow us on Facebook now: