We prospectively investigated the appropriateness of Mechanism of Injury as an exclusive indicator for trauma center triage. For all patients transported to our level 1 trauma center, EMS personnel identified applicable American College of Surgeons' Committee on Trauma field triage guidelines. A total of 112 questionnaires were completed. Mechanism of injury was the only reason for trauma center transport in 29. Neither intubation nor emergent surgery was required in any of these patients, and all survived. Only two had an ISS > 15. The remaining 83 patients had an 11% mortality rate. Fourteen (16.9%) had ISS scores > 15. Defining an ISS of 16 or greater as severe injury, mechanism of injury alone had a positive predictive value of only 6.9%. Mechanism of injury may not, by itself, justify bypass of local hospitals in favor of trauma centers.