To evaluate current morbidity and mortality and to define the best strategy of management, we retrospectively reviewed the clinical histories of 36 patients (24 males and 12 females) who underwent repair of symptomatic, nonruptured abdominal aortic aneurysms (AAAs) between April 1, 1987, and April 30, 1992, at the Mayo Clinic (3.2% of 1111 patients with AAA repair). Ages ranged from 54 to 94 years (mean 75 years). All patients were hemodynamically stable and presented with abdominal and/or back pain of 1 to 60 days' duration (mean 11.6 days). The diagnosis of AAA was confirmed by CT scan in 26 patients, ultrasonogram in seven, and plain abdominal films in three. Fourteen patients (38.9%) were operated on emergently within 4 hours of admission, 11 (30.5%) between 4 and 24 hours, and 11 between 24 hours and 7 days following presentation (mean 28.9 hours). Eight (22.2%) had inflammatory aneurysm. AAAs were repaired with a straight graft in 17 patients and a bifurcated graft in 19. Complications occurred in 24 patients (66.7%). Mortality was 11.1% (4/36). The association between emergency repair (< 4 hours) and 60-day mortality was significant (p < 0.05). There were no deaths among those patients whose operation was delayed. Comparison to a matched control group of 72 patients who underwent elective AAA repair revealed an increased incidence of inflammatory aneurysm and female gender among our study group. The symptomatic patients had larger aneurysms (6.5 vs. 5.6 cm, p < 0.05) and required more intraoperative transfusions. Intensive care unit and hospital stay was longer in the symptomatic patients (p < 0.001); morbidity was markedly increased (p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)