OBJECTIVE To review the effects of exogenous estrogen and progestin on metabolic risk factors for coronary artery disease in women. METHODS Review of selected literature. METHODS Population studies and clinical trials. METHODS Premenopausal and postmenopausal women. METHODS Exogenous gonadal hormones in oral contraceptives and hormone replacement regimens. METHODS Lipoprotein, hemostatic, carbohydrate, and blood pressure metabolic parameters. RESULTS Favorable lipoprotein changes have been demonstrated in both observational studies and clinical trials of effects of exogenous hormones on cardiovascular risk factors in women. These include declines in low-density lipoprotein, apoprotein B, and lipoprotein(a), and increases in high-density lipoprotein (HDL), HDL2, and apoprotein A-I. Hormone replacement effects on triglyceride are minor and, in most patients, probably benign. Evidence is unconvincing that clinically significant changes in clotting factors, carbohydrate metabolism, or blood pressure take place as a result of postmenopausal hormone interventions. In fact, carbohydrate metabolism and blood pressure may be improved slightly. Metabolic studies do not, thus far, provide any contraindications to either estrogen replacement therapy (ERT) or hormone replacement therapy (HRT) in appropriately selected subjects. However, because studies of metabolic risk factors generally have been done in patients who were not hyperlipidemic, hypercoagulable, hyperglycemic, or hypertensive, little is known about the metabolic effects of ERT or HRT on pre-existing metabolic abnormalities.