In two separate studies, charts of 169 all-terrain vehicle (ATV) accident victims admitted to the emergency department of Desert Hospital in Palm Springs, California, were reviewed. Twenty-four percent of the cases were women, 30% were hospitalized, and 1% (two patients) died. The youngest patient was 3 and the oldest was 76. About 31% had been drinking, and the major type of bony injury (16%) was to the clavicle, ribs, or sternum. The accident rate was calculated as ten accidents per 1,000 ATV rider days, which is comparable to the ski accident rate of six per 1,000 skier days. The three-wheeled variety of ATV is responsible for nearly all the accidents.