A number of epidemiological studies have clearly shown that post-menopausal women on hormone therapy (which tends to simulate normal ovarian production) have a reduced risk of cardiovascular disease (coronary heart disease, stroke and thrombotic events). In fact most of the studies have involved equine oestrogen (Premarin) taken orally. The effects of oestrogens and the progestins depend on the type of administration (oral or percutaneous administration) and the variety of the drug chosen and finally is also dose dependent. The most favourable effect is obtained in normolipidaemic women with the combination of conjugated oestrogens given orally and a non-androgenic progestins. Such therapy is associated with an increase in HDL-cholesterol and a decrease in LDL-cholesterol. HDL subfraction analysis shows that HDL2 are the main species involved in this increase. The mechanism of action of oestrogens and progestins can be summarized as follows: oestrogens stimulate hepatic triglyceride secretion, inhibit the action of hepatic lipase, augment LDL breakdown via the cellular receptor apo B-E and may decrease LDL oxidability and Lp(a) levels. Although several points remain obscure, we may notice that most of studies show that the atherogenic profile of the women who are currently being treated tends to improve.