Epidemiological observations, clinical studies, and basic laboratory research suggest that oestrogen replacement therapy is associated with beneficial cardiovascular effects in postmenopausal women. Oestrogen has a multitude of biological effects that may account for this apparent benefit (which remain to be proven in randomized clinical trials), including favourable effects on the lipid profile, a direct effect on the vascular endothelium with increased nitric oxide bioactivity, and improved fibrinolysis. However, long-term oestrogen therapy increases the risk of breast and endometrial cancers. Raloxifene, a benzothiophene derivative that binds to the oestrogen receptor, is a selective oestrogen receptor modulator, producing oestrogen-agonistic effects in some tissues (liver, bone), and oestrogen-antagonistic effects in others (breast, uterus), and may prove to be an option for women with atherosclerosis and its associated risk factors who might benefit from oestrogen therapy. This review updates the current knowledge of the biological effects of oestrogen and selective oestrogen receptor modulators of potential cardiovascular importance in postmenopausal women.