Twenty-eight patients with abdominal aortic aneurysm were examined by computed tomography (CT) and aortography. They subsequently underwent aneurysmectomy and reconstruction of the aorta. CT provided in most of the cases the same or more accurate preoperative information than aortography. CT is comfortable for the patient, less invasive and faster than aortography and can be done as an outpatient procedure. Thus, we recommend CT to be the primary method for preoperative evaluation of abdominal aortic aneurysm. In selected cases aortography gives additional information regarding the relationship to the renal arteries (when the aorta is very tortuous), the occurrence of renal artery stenosis, and peripheral vascular disease.