An essential feature of the trauma center concept is the rapid delivery of patients with complicated injuries to a regional trauma center directly from the site of injury. A variety of triage instruments have been proposed to aid the prehospital personnel in making this difficult triage decision. We used a combination of prospective and retrospective analysis to evaluate and compare the performance of 11 recommended triage instruments on the same trauma population. Of the 130 patients evaluated by paramedics in a semirural area, 41 patients were considered desirable for trauma center triage. These patients were identified by either the absence of vital signs in the prehospital setting, death in the emergency department, immediate surgery other than for orthopedic extremity injury, or immediate admission to the intensive care unit. All subsequent in-hospital deaths occurred in the group of patients identified as deserving trauma center triage. Of the triage instruments, the Kane's "revised" checklist provided the largest improvement in odds against needing a trauma center when the triage instrument is negative. Of the triage instruments with a sensitivity greater than 70%, the respiratory/systolic pressure/Glasgow Coma Scale (RSG) score provided the largest improvement in odds for needing a trauma center when the triage instrument is positive. Although no triage instrument performed ideally, the patients missed by the triage instruments having a sensitivity greater than 70% were hemodynamically stable. Transfer of such patients to a trauma center following determination of the extent of underlying injury at a referring emergency department should be possible.