Gonadotropin-releasing hormone (GnRH) agonists are associated with greater risk of coronary heart disease and myocardial infarction in men with prostate cancer, but little is known about potential impact on cardiovascular mortality. We assessed the relationship between GnRH agonists and cardiovascular mortality in a large randomized phase III trial of men treated with or without adjuvant goserelin after radiation therapy (RT) for locally advanced prostate cancer.