The importance of estrogen action in maintaining health is illustrated by the increase in incidence of many disorders after the loss of circulating estrogen which accompanies menopause. Serious health and economic costs are incurred by the increased rates of heart disease, osteoporosis, vasomotor symptoms (hot flashes) and other disorders. Although the risk of these diseases may be reduced by the administration of replacement hormones, many women elect not to begin or to continue hormone replacement therapy (HRT). This may be due in part to concerns about increased risk of cancer and of other diseases whose association with HRT is uncertain. Epidemiologic studies show decreased risk of some of these syndromes and symptoms in populations whose intake of phytoestrogen-containing foods is significant. Since these dietary compounds show some estrogenic activity, controlled studies have been carried out to examine the relationship between intake of isoflavones, the most metabolically active of these phytoestrogens, and the disorders associated with menopause. There appear to be some significant benefits of isoflavones after menopause, without the increased risks of cancer which may be associated with traditional hormone replacement.