Sixty-four aortic aneurysms and four aortic dissections were studied in two planes with respect to thrombosis, calcification, bleeding and intimal tears. The features demonstrated in 13 abdominal aneurysms by plain films, computed tomography and angiography are described, and the sonographic features in seven. Sonography should be used as a screening method when an abdominal aneurysm is suspected. CT is indicated for thoracic aneurysms, unsatisfactory sonography, suspected involvement of visceral arteries, aortic or iliac artery occlusion, or where bleeding, imminent rupture or dissection are suspected. CT and angiography are complementary methods.