Mortality rates for patients undergoing surgery for ruptured abdominal aortic aneurysm (RAAA) remain high. The high cost of providing care for these patients mandates that proposed treatment protocols be evaluated for their cost-effectiveness. This study assessed costs related to outcome in different groups of patients with RAAA. From July 1987 to December 1993, 140 patients underwent emergency surgery for RAAA. Complete data on preoperative haemodynamic status, blood transfusion requirements, intensive cave unit (ICU) stay and other hospital costs was available for 94 patients. Seventy-seven males (mean age 71.6(6)) and 17 females (mean age 77.2(6)) underwent surgery. Known risk factors including age (< or >70 years), shock on admission (systolic blood pressure (BP) < or >90 mm Hg), sex, and acute renal failure were analysed. Far the purpose of comparison, costs (pound) were assessed by the ESRI (Economic and Social Research Institute of Ireland) based on 1992 prices. The overall survival rare eons 48%; 53% among males and 24% among females (p<0.05, Chi-squared test). In addition to having a significantly worse outcome than males, female patients with RAAA also had longer hospital and ICU stays and this was reflected in significantly greater expenditure. Similarly, male patients >70 years old presenting with haemodynamic instability had significantly longer hospital and ICU stays than younger male patients. The average cost per RAAA survival (pound 12 945) in this series is not prohibitive, and the greater cost in high risk groups should not discourage intervention.