Approximately 20 million women worldwide use hormone replacement therapy (HRT). Formerly, it was thought to confer beneficial cardiac protection and reduce osteoporosis in addition to relieving the symptoms of menopause. However, many recent trials have contradicted these beliefs. The risk of breast cancer associated with HRT use has been well documented but underestimated. Many recent trials have reported higher than expected breast cancer incidence rates, particularly associated with combined HRT. Although it was believed estrogen conferred cardiac protection and reduced the incidence of myocardial ischemic events and cerebrovascular accidents, the more recent literature indicates that this is not true and that HRT users have a higher risk of cardiac and cerebral events. The role of HRT in clinical practice has been redefined. It is no longer an acceptable form of treatment for most women. The evidence indicates that the use of long-term HRT is no longer clinically justifiable.