SOME unusual examples of intraperitoneal bleeding which have been encountered recently have stimulated the authors to review all patients with this condition in the Oxford group of hospitals over the last six years (1951)(1952)(1953)(1954)(1955)(1956), a total of 129 cases. We have excluded from consideration conditions merely producing blood-stained extravasations of fluid, (for example, acute pancreatitis and mesenteric thrombosis), and included only those patients where an extensive collection of frank blood was found either at operation or post-mortem. The aetiology and mortality of these cases, together with the accuracy of me-operative or me-autopsy diagnosis, is shownOf the uatients in this series 87 (68 ver cent) had bleeding d gynaecological origin' (ruptured ectopic pregnancies or ruptured follicular cysts) and 30 cases (23 per cent) followed trauma to spleen, liver, or both these organs. There were also 4 ruptured aortic aneurysms leaking into the peritoneal cavity and 2 severe post-operative haemorrhages. The 6 remaining examples, all of unusual origin, will be considered in detail later. As regards accuracy of diagnosis, it was evident in nearly all cases that an intra-abdominal disaster had occurred. The exceptions occurred in the 8 patients dying after splenic and/or hepatic trauma. All these were admitted with overwhelming and rapidly fatal head injuries, the abdominal lesions being found incidentally at autopsy, often accompanied by multiple injuries elsewhere.The common gynaecological emergencies and the traumatic haemorrhages uncomplicated by head injuries were correctly diagnosed pre-operatively in the majority of cases (87 per cent), as can be seen from Table I. Of 74 patients where this information was available, the general practitioners had reached a correct diagnosis in 50 per cent of cases, and had invariably recognized the urgency of the condition with which they were called upon to deal.The single fatality in the cases of gynaecological origin was unusual and of interest. She was a girl of 17 with known thrombocytopenic purpura who had had a splenectomy 5 years previously, but whose bleeding tendency had persisted. She died shortly after reaching hospital and autopsy revealed a massive haemoperitoneum due to haemorrhage from a ruptured follicular cyst.There was only I death among the 22 patients with traumatic haemoperitoneum uncomplicated by head injury. In this case the principal cause of haemorrhage was a tear of the middle colic vessels, but, as well as this, there were lacerations of liver, colon, duodenum, and kidney.All 4 patients with intraperitoneal rupture of aortic aneurysms were undiagnosed and all died. Of the 2 post-operative haemorrhages, one followed a pancreatectomy for carcinoma and was fatal, the other followed appendicectomy and the patient recovered after re-exploration and blood transfusion.The rare cases, not surprisingly, were all incorrectly diagnosed before surgery or autopsy and the mortality in this group was high, there being only I survivor in the 6 patien...