Nearly 90% of patients with clear-cut hyperlipidemia seen in clinical practice have type II or IV hyperlipoproteinemia. Previous studies have shown that these syndromes have different distributions of coronary artery atherosclerosis and different outcomes after coronary bypass grafting. A characteristic pattern of vascular calcification on chest films might have some prognostic value. Therefore, to determine the location and extent of aortic root and coronary artery calcification seen on chest films, 33 consecutive patients with type II and 17 with type IV hyperlipoproteinemia were studied who were admitted for coronary arteriography between 1970 and 1982. Among the 33 patients with type II disease, 21 women and 12 men, 22 had radiographically visible calcification that was different in distribution from that usually found in atherosclerotic disease. The ascending aorta was involved in 21 and the arch in 12. In eight patients, the calcium outlined a distinctive narrowing of the ascending aorta. Six patients had significant left ventricular obstruction; in five it was from aortic valve stenosis. Of the 17 type IV patients, 16 men and one woman, none had aortic calcification or left ventricular outflow obstruction, and only one had coronary artery calcification. These data demonstrate that patients with type II hyperlipoproteinemia have severe calcific atherosclerosis of the aortic root that often is visible on chest films. Such calcification may alert physicians to the presence of type II hyperlipoproteinemia and the high probability of severe coronary artery disease.