Spiral computed tomographic (CT) angiography involves a timed intravenous injection of contrast material, rapid data acquisition, reconstruction at narrow intervals, image editing, and maximum intensity projection image processing. Spiral CT angiography of the abdominal aorta was performed in 28 patients for preoperative aneurysm assessment. The results were unsatisfactory in only two patients; 54 main and 12 accessory renal arteries and 26 aortic aneurysms were seen. In 17 of the 26 patients with aneurysms, there was surgical confirmation of the CT angiographic findings regarding size, suprarenal extension, and distal extent of the aneurysms, with no additional renal arteries detected. With this technique, the relationship of an aneurysm to renal, superior mesenteric, and inferior mesenteric arteries can be assessed. CT angiography also depicts the proximal extent of an aneurysm, which is the single most crucial piece of preoperative information; an associated renal artery stenosis or occlusion; or an accessory renal artery. CT angiography can be performed as an outpatient procedure before vascular surgery with fewer risks, with lower radiation dose, and at one-third the cost of conventional angiography.