The experiment was aimed primarily at inducing moderate atherosclerosis to investigate the role of behavioural and emotional factors in diet-induced atherosclerosis in rabbits. The experimental rabbits (group E, n = 10) were offered 130 g standard pelleted feed mixed with 1 egg yolk daily, whereas the control rabbits (group C, n = 9) were fed the same feed but without egg yolk. Altogether the E rabbits were offered 64 egg yolks within a period of 2 months. Total plasma cholesterol was estimated before and after the experimental period. The degree of atheroma was estimated quantitatively as the percentage of the aorta surface affected. Mixing the egg yolk with pelleted feed resulted in the E rabbits consuming on average 20.1 g cholesterol during the experimental period as compared to 6.9 g cholesterol consumed by C rabbits in normal feed. There was no significant effect of feeding egg yolk on total plasma cholesterol. A significant diet x sex interaction effect (P = 0.013) on total plasma cholesterol after the experimental period was found. Not one of the rabbits either group E or C developed visible atherosclerosis.