Hypercholesterolemia and hyperlipidemia have been important in human health as factors that induce atherosclerotic lesions in brain and heart blood vessel. Various experimental studies have been done to prevent and treat atherosclerotic lesions in animals. In the present study, we assessed the suitability of chickens as experimental animal for atherosclerosis. Newly hatched chicks were fed on 1.0%-or 0.1%-cholesterol(CHO) containing feed. After 3 and 6 months, total cholesterol levels in the sera and histological changes in the aorta and coronary artery of chicks fed on 1.0%-CHO-containing feed for 3 and 6 months, intimal thickening and marked accumulation of foam cells were observed. Endothelial cells had disappeared in the aorta of these chicks. A slight accumulation of foam cells was observed in the aortic intima of chicks fed on 0.1%-CHO-containing feed. In the coronary artery, a remarkable thickening of intima with accumulation of foam cells and a marked stenosis of coronary space were observed in chicks fed on 1.0%-CHO-containing feed. The results of present study indicate that the chicken can be a useful experimental animal in the study of hypercholesterolemia, hyperlipidemia and atherosclerosis.