We reviewed 43 patients treated from 1984 to 1988 for open fractures of the pelvis. There were four Gustilo type I wounds, seven type II and 32 type III; 22 fractures were stable and 21 unstable. The overall mortality was 30%; the average Injury Severity Score was 30, being 26 in the survivors and 40 in the fetal cases. We analysed the influence of a number of factors on the mortality rate. The most important were the ISS and the age in years, while the presence of a type III wound and instability of the fracture also had an influence. We describe two simple methods of assessment of the prognosis in individual cases, based on these factors.