Since systemic administration of synthetic retinoids was introduced into dermatology and oncology, side-effects of synthetic vitamin-A derivatives on lipid and lipoprotein metabolism have become apparent. Retinoids of the first and second generation, 13-cis-retinoic acid and etretinate, are capable of inducing secondary hyperlipoproteinemias. For further evaluation of the atherogenic risk of retinoid-induced hyperlipoproteinemias, the most relevant effects of natural and synthetic retinoids on lipid metabolism as well as the interactions between lipid and retinoid metabolism are considered in this review.