BACKGROUND Off-road motorsports are an increasing popular activity, yet the relative safety profile of all-terrain vehicles (ATV) to off-road motorcycles (ORMC) has not been compared. METHODS A retrospective review of the 2002-2006 US National Trauma Data Bank of ATV and ORMC crash victims. Patients were described according to demographic (age, sex, race and ethnicity, insurance status) and injury characteristics (Injury Severity Score, hypotension, motor component of the Glasgow Coma Score, presence of a severe head or extremity injury) known to affect trauma outcomes. Logistic regression evaluated the independent effect of an ATV vehicle on mortality, intensive care unit (ICU) admission, and placement on a ventilator relative to ORMC. The anatomic distribution of severe injuries was compared between survivors and decedents within each vehicle type. RESULTS A total of 34,457 patients met inclusion criteria, of whom, 24,582 were ATV patients and 9875 were ORMC patients. ATV patients had 51% higher risk-adjusted odds of death (OR 1.51; 95% CI 1.03-2.20), 55% higher risk-adjusted odds of being admitted to an ICU (OR 1.55; 95% CI 1.42-1.70), and 42% higher risk-adjusted odds of being placed on a ventilator (OR 1.42, 95% CI 1.17-1.72) compared to ORMC crash victims. Decedents in both vehicle types were more likely to suffer severe head, thoracic, and abdominal injuries relative to their surviving counterparts. CONCLUSIONS For injured riders, ATVs are associated with increased mortality and higher resource utilisation compared to ORMCs. Both groups suffer distinct anatomic injuries, suggesting the need for focused areas of injury prevention planning and research.