Horseback riding is more dangerous than motorcycle riding, skiing, football, and rugby. The purpose of this study was to identify the incidence and injury patterns, as well as risk factors associated with severe equestrian trauma. All patients with major equestrian injuries (injury severity score > or = 12) admitted between 1995 and 2005 were reviewed. A 46-question survey outlining potential rider, animal, and environmental risk factors was administered. Among 7941 trauma patients, 151 (2%) were injured on horseback (mean injury severity score, 20; mortality rate, 7%). Injuries included the chest (54%), head (48%), abdomen (22%), and extremities (17%). Forty-five percent required surgery. Survey results (55%) indicated that riders and horses were well trained, with a 47% recidivism rate. Only 9% of patients wore helmets, however, 64% believed the accident was preventable. Chest trauma previously has been underappreciated. This injury pattern may be a result of significant rider experience. Helmet and vest use will be targeted in future injury prevention strategies.