The relation between hormone use in postmenopausal women and cardiovascular disease remains controversial. Whereas epidemiologic studies and clinical studies assessing several intermediate cardiovascular disease endpoints indicate a clear benefit for the primary prevention of coronary artery disease (CAD), secondary-prevention trials of relatively short duration do not support a benefit. More recent epidemiologic studies continue to supply evidence that long-term postmenopausal hormone therapy may reduce the risk for CAD in healthy women. Adding progestin to the regimen does not appear to attenuate the benefit. The Nurses' Health Study and studies from Europe, where estradiol is the commonly prescribed form of estrogen, suggest that estrogen at lower doses may confer similar benefit. However, remarkably consistent data from both epidemiologic studies and a secondary-prevention trial indicate a significantly increased risk of venous thromboembolism with hormone use. The data on stroke are inconclusive, but there is little evidence to suggest a benefit of hormone use on either ischemic or hemorrhagic stroke. Existing evidence indicates that the various potential benefits and risks should be weighed carefully when prescribing hormone therapy to a postmenopausal woman.