This prospective cohort study was performed from 1994 to 1996 to compare the impact of scene disposition on prehospital and hospital costs incurred by rural trauma patients transported to a trauma center by helicopter or ground ambulance. The study included all rural adult injury victims who arrived at the tertiary trauma center by ambulance within 24 h of injury. Inclusion criteria consisted of inpatient admission or death in the emergency department, and any traumatic injury except burns. Data collected included mortality, mode of transport, Injury Severity Score (ISS), and costs from impact to discharge or death. Of 105 study patients, 52 initially went to a rural hospital, while 53 went directly to the trauma center. There was no significant difference in survival in the two groups. The ISS was significantly higher for patients taken directly to the trauma center from the scene. The ISS of trauma patients transported from the rural hospital was highest for patients sent by ground transport. The prehospital transport costs were significantly more for patients transported to a rural hospital first. The costs incurred at the trauma center were highest for those patients transported directly from the scene. Many severely injured patients were initially transported to a rural hospital rather than directly to the trauma center. At both the scene and rural hospital, consistent use of triage criteria appeared to be lacking in determining the severity of injury, appropriate destination, and mode of transport for trauma patients. Since no significant difference in prehospital helicopter and ground transport costs was demonstrated, the decision on mode of transport should be in the best interest of patient care.