The mortality among 604 patients with pelvic fractures was 12%. Pedestrian accidents were the etiologic agent in 27% of the patients, but accounted for 49% of the deaths and for 73% of the deaths primarily due to pelvic fractures. Although 71 of the 72 patients who died sustained concomitant major injuries (mean, 3.1), 60% of the deaths (43 patients) were attributed entirely or in part to pelvic fractures. Of particular interest were the 26 patients in whom the pelvic fracture was the primary cause of death. Ninety-three percent were in shock or had clinical evidence of hypovolemia at the time of admission. Eighteen patients (69%) exsanguinated from their pelvic fractures shortly after hospital admission (mean, 9 hours). They were more elderly than the eight patients who survived their initial resuscitation, but subsequently died of sepsis or of renal failure (mean, 62 vs. 38 years). Sepsis arising in the pelvic hematoma and acute renal failure induced by pelvic hemorrhage and/or pelvic sepsis each accounted for 15% of the deaths. Ninety-one percent of the patients who died primarily of their pelvic fracture had a single or double break in the pelvic ring. Thirty-one precent had open pelvic fractures, and injury associated with a 50% mortality. Twenty-three percent had pelvic fracture related iliac or femoral vessel disruptions, an injury associated with a 75% mortality. Mortality in these patients clearly resulted from ineffective control of pelvic hemorrhage and from the inability to prevent sepsis in the pelvic hematoma.