Death or serious injury may occur as the result of accidents involving three- and four-wheeled recreational vehicles. Thirty-two cases of such trauma requiring hospitalization at the University of Missouri Hospital were reviewed, and followup questionnaires sent to each patient. Head and extremity trauma was nine times as frequent as torso injuries. Males were injured in 81% of the cases, and the average age of all patients was 18.6 years. Fifty per cent required intensive-care monitoring and 74% required surgery. Two patients died of head injuries. Of the 25 survivors who responded to the questionnaires, 44% reported either inability to return to work or substantial interference with daily living due to their injuries. Inexperience riding the vehicle, prior use of alcohol, and lack of protective riding apparel were frequently cited as contributing factors in these injuries.