Coronary heart disease (CHD) in women is an important public health problem although not one that generates much public concern. Most doctors seem to believe that hormone replacement therapy (HRT) can reduce the incidence of heart disease in women after the menopause but the evidence for this is contentious. Epidemiological studies have consistently shown a cardioprotective effect for HRT. Critics suggest that these studies are flawed because women who take HRT may be healthier than others in ways that have not been assessed in the studies. Large primary prevention trials are under way but such studies are extremely difficult to design and conduct and may yet fail to provide the conclusive results needed to resolve the debate. An important randomised trial of HRT in secondary prevention has recently been published showing no benefit in the short term but a possible long term benefit. In practice, the potential public health impact of HRT in the prevention of CHD will be limited by current public attitudes to the safety of HRT, and the reluctance of older women to take HRT for prolonged periods. Women with established CHD or diabetes might benefit more from HRT, but are currently less likely to receive it.