Cardiovascular disease and erectile dysfunction (ED) are frequently comorbid. Therefore, it is important to consider the risk of renewed sexual activity after successful treatment of ED in men with cardiovascular disease. This article reviews the limited existing knowledge of the metabolic and cardiovascular demands of sexual activity. Evidence suggests that there is a small increase in cardiovascular risk related to sexual activity. Overall, however, the metabolic and cardiovascular demands of sexual activity are modest, and regular physical activity can almost eliminate the increase in risk occurring during sex. In addition, it is unlikely that any direct effect of a phosphodiesterase 5 inhibitor increases cardiovascular risk in patients with cardiovascular disease, absent the coadministration of organic nitrates.