Although the operative mortality following elective aneurysmectomy has achieved satisfactory results, that following surgery for ruptured abdominal aortic aneurysms (AAAs) remains high. The purpose of this study was to identify the factors affecting the mortality rate associated with the treatment of ruptured AAAs. Between 1978 and 1999, 33 patients underwent emergency surgery for a ruptured AAA. The operative mortality was 33.3% and in-hospital mortality was 6.0%. Hypotension, defined as a systolic blood pressure <80 mmHg, was seen in 19 patients at the time of presentation, 9 of whom underwent surgery in this state. In the remaining 10 patients, it was possible to increase the systolic blood pressure to > or =80 mmHg preoperatively. Of the 11 patients who died within 30 days of surgery, 9 had hypotension at the time of induction of anesthesia and only 2 had a systolic blood pressure of > or =80 mmHg. A satisfactory outcome was achieved in patients whose condition met the following criteria: a systolic blood pressure > or =80 mmHg at the time of operation, minimal aortic cross-clamping time, less blood loss and blood transfusions, and a shorter operation time to repair the ruptured AAA. Concomitant heart disease was also found to be an important prognostic factor.