Cardiovascular disease (CVD) is the leading cause of mor-tdity in women in developed counries, resulting in 500,000 deattrs annually in the United States, half of which are due to coronary heartdisease (CIID)(1). Aprotectiverole of estrogen is suggestedby tlre low risk of CIID in premenopausal women, narrowing of the gender gap in CHD risk after menopause, the high risk of CHD in young women with bilateral oophorectomy not ffeated with esffogen, and epidemiologic data sup-porting lowered CIID risk with postmenopausal hormone replacement therapy (I {RT). Nearly 40Vo of women in the US will be above age 45 by the year 2000 (2), underscoring the potential public healttr impact of an intervention like [IRT. This review examines the epidemiologic evidence and proposedbiologic mechanisms forCHD riskreduction with HRT.