In 42 patients, massive haemorrhage following comminuted pelvic fractures was treated by operation through a mid-line, Pfannenstiel, anterior iliac crest-femoral or posterolateral approach, or using these in combination. The superior and inferior gluteal, pudendal and obturator arteries were the usual source of bleeding. Bleeding from the pelvic bone tissue was of minor importance. Temporary compression of the abdominal aorta was sometimes required to help control bleeding before ligation of injured vessels could be accomplished. An average of nine units of blood was given to each patient before operation and 30 units during or after the procedure. Of the 12 deaths, only three were attributable to bleeding from the pelvic fractures, indicating the value of operation in the treatment of massive haemorrhage from such injuries.