Riding all-terrain vehicles (ATVs) is a popular recreational activity, with approximately 1.5 million users in Canada. Despite legislation aimed at reducing injury rates, ATV-related incidents remain a major cause of trauma and death. This paper reviews the epidemiology of major injury associated with ATV use in Nova Scotia. The Nova Scotia Trauma Registry was used to identify all adults over age 15 who sustained major ATV-related trauma (Injury Severity Score [ISS] >/=12) within a 5-year period. Demographic variables, temporal statistics, alcohol use, helmet use, injury characteristics and injury outcome variables, including ISS, length of stay (LOS), Glasgow Coma Scale score and discharge status were evaluated. Twenty-five patients met the inclusion criteria. Most (92%) were males, and 64% were between 16 and 34 years of age. Most injuries occurred between 1300 hrs and 1900 hrs, 52% occurred on the weekend, and 40% occurred in the spring. The average ISS was 22.1, and injuries to the central nervous system comprised 39% of all major injuries. Alcohol was involved in up to 56% of all incidents, and only 4 patients (16%) were known to be wearing a helmet at the time of injury. Average hospital LOS was 21.6 days. ATV-related incidents are a continuing source of major injury. This paper describes the epidemiology of ATV-related major trauma presenting to the sole tertiary care referral centre in one province. Information gained from this study should be used to influence ATV public education programs.