To evaluate the hypothesis that all victims of severe blunt trauma require a pelvic radiograph, we prospectively studied all such patients admitted to the Southern New Jersey Regional Trauma Center during a seven-month period. All patients were classified as unconscious; impaired; awake, alert, and symptomatic; or alert, oriented, and asymptomatic for pelvic fracture on admission. All underwent a plain anterior-posterior radiograph of the pelvis. A total of 265 patients were studied and 26 pelvic fractures were identified. These occurred in seven of 36 unconscious patients, 11 of 96 impaired patients, and eight of 23 symptomatic patients. No fractures were identified in 110 awake, alert, oriented, and asymptomatic patients (P less than .0001). We conclude that pelvic radiographs are required in unconscious or impaired victims of severe blunt trauma and those with signs or symptoms of pelvic fractures but are not required in the awake, alert, and asymptomatic patient.