Background: Risks and benefits of postmenopausal hormone therapy remain highly controversial. After publication of the Women's Health Initiative hormone trials and several other major trials, the American Heart Association designated postmenopausal hormone therapy as 'Class III', if initiated for the purpose of cardiovascular disease prevention. Subsequent post hoc analyses of the Women's Health Initiative data have renewed enthusiasm for hormone therapy among younger postmenopausal women. Objective: To review data from randomized clinical trials that have assessed cardiovascular outcomes of hormone therapy including coronary heart disease, stroke, peripheral arterial disease, and venous thromboembolism. Methods: The review focuses on cardiovascular effects of hormone therapy only and does not attempt to integrate potential risks and benefits related to symptoms, cancer, osteoporosis or other noncardiovascular effects of postmenopausal hormone therapy. The literature search included original trial publications, post hoc analyses, and aggregate data from meta-analyses published in English and accessible to the author in full-text format for detailed analysis. Results/conclusion: Risks of hormone therapy seem to predominate among older postmenopausal women. Data among younger women close to menopause are insufficient to recommend such therapy for cardiovascular disease prevention. © 2009 Informa UK Ltd. All rights reserved.