A clinical prognostic scoring system for patients with abdominal aortic aneurysm and audit of the sequelae of a sample population in Glasgow, are described. Randomly selected case notes of 500 patients, representing 41.6% (500 of 1202) of the total population treated in Glasgow hospitals with general surgical units (as opposed to vascular units) between 1980 and 1990, were examined for risk factors. These were then related to the operative and postoperative hospital mortality. Initial univariate analysis showed the outcome to be significantly influenced by the following factors: age (P = < 0.01), rupture (P = < 0.001), shock (P = < 0.001), myocardial disease (P = 0.08), cerebrovascular disease (P = 0.03), renal disease (P = 0.03) and size of the aneurysm (P = 0.06). Using multivariate analysis, the following independent risk factors were identified: age (P = 0.02), shock (P = < 0.001), myocardial disease (P = 0.02), cerebrovascular disease (P = 0.02) and renal disease (P = 0.003). Rounding of the regression coefficients created a simple risk score: risk score = (age in years)+(17 for shock)+(7 for myocardial disease)+(10 for cerebrovascular disease)+(14 for renal disease). Subsequent evaluation of the scoring system showed that the mortality rate increases in proportion to the score. Other findings are analysed and discussed.