The effect of dietary ergotamine on pre-lesional indicators of atherosclerosis was studied in rabbits. The experimental purified diets contained 0.08% (w/w) cholesterol and either 0, 40 or 200 mg ergotamine-tartrate/kg. After 6 wk, serum total cholesterol concentration and the ratio of serum total cholesterol: high-density lipoprotein-cholesterol were significantly increased by ergotamine in a dose-dependent manner. Dietary ergotamine raised the total level of glycosaminoglycans and the relative proportion of chondroitin sulphate in the abdominal aorta. It is suggested that dietary ergotamine is atherogenic in the rabbit.