The total lipid content in the livers of rats consuming cooked whole eggs as the only source of food for 21 days was elevated to three times that of control animals. The incorporation of 14C-labelled amino acids into serum low-density lipoprotein apoproteins was increased by 52% in these rats, without affecting the incorporation into serum albumin and liver total proteins. The turnover of low-density lipoprotein in these egg-fed rats appears to be very high.