The Tytherton Fun Ride (25 March) has been cancelled due to poor ground conditions.
Up to 400 riders were expected to ride the courses across Field Farm, near Chippenham, Wiltshire to raise money for local charities and the Wiltshire Air Ambulance.
The six and 12 mile fun rides which contain optional jumps, have been running for 20 years — and up until now only Foot and Mouth Disease prevented the event from taking place.
“The ride is always such fun – people come from far and wide,” said ride secretary Sheree Pitt. “It is such a shame to cancel but we have to think of the riders, horses and the farmland.”