Between January 1979 and May 1987, 167 patients with abdominal aortic aneurysm or iliac artery aneurysm were subjected to surgery. Of these 167 aneurysms, 22 (13.1%) were ruptured, including two cases of impending aneurysmal rupture. Patient ages ranged between 30 and 83 years (mean: 67.5 years), and there was no significant difference from that of the elective group during the same period. The causes of aneurysm were non-specific inflammation in two patients, mycosis in one and arteriosclerosis in 19. The mean diameter of the aneurysm was 8.7±2.4 cm, which was significantly larger than that of the elective group (p<0.001). The mean amount of blood loss during surgery was 6077±4080 g, which was significantly more than that of the elective group (p<0.001). There was no significant difference in the operation time between the two groups. Postoperatively, there were eight (36.4%) hospital deaths: three from acute circulatory failure and heart failure, two from acute respiratory failure or acute renal failure, and three from MOF due to complications. The prognosis of surgically-treated ruptured abdominal aortic aneurysm has been poor. Although perioperative intensive care is expected to improve the outcome, the only strategy for really resolving this problem is diagnosis and treatment before rupture.