BACKGROUND: On April 8, 1998, an F5 tornado touched down in two counties of Alabama producing a wide path of destruction. The presence of a regional trauma system in this area presents an opportunity to evaluate the effectiveness of the system in responding to the victims of this natural disaster. METHODS: Emergency room logs and the regional trauma system database were searched for all patients treated for injuries sustained from the tornado, and medical records were reviewed for demographic information, mode of transportation to hospital, injuries, treatment, and outcome. Fatalities were identified by means of the coroner's office. RESULTS: A total of 224 patients were evaluated at nine area hospitals, of whom 63 (28%) required admission. There were 32 deaths: 30 persons were dead at the scene, and 2 patients subsequently died at Level I trauma centers. Among patients with nonfatal injuries, 39% were managed at Level I facilities, 46% at Level III facilities, and 15% at nontrauma facilities. Forty patients (55%) seen at Level I facilities required admission compared with 15 patients (17%) at Level III facilities and 8 patients (29%) at nontrauma facilities; Level I facilities also had the highest Injury Severity Score. Of patients requiring admission, 83% were transported by emergency medical services; these patients also had the highest Injury Severity Score. CONCLUSION: The regional trauma system facilitated appropriate and efficient triage to system hospitals, routing the most severely injured patients to the Level I centers without overwhelming them with the more numerous, less severely injured patients.