This review provides current information on the potential mechanism by which steroids are cardroprotective and how hormone replacement therapy with estrogen or combined estrogen therapy (re. estrogen and progesterone or androgen) can modulate vascular responsiveness. Substantial evidence events to suggest that nitric oxide clays an important role in regulating basal vascular tone as well as vascular responsiveness. Nitric oxide synthesis in endothelial cells and the underlying vascular smooth muscle appears to be directly regulated by estrogen favels in the past 2 years specific estrogen receptors have been described and cloned and are now referred to as α and β estrogen receptors. The development of specific agonists for each receptor may ultimately lead to highly selective compounds whose effects may be specific for target system if this occurs, it may be possible to effectively treat or prevent cardiovascular disease and osteoporosis with these agents. Furthermore, depending on the distribution of these receptors in men and women, therapeutic possibilities may exist for both sexes. with minimal side effects.