There is increased awareness regarding the close association between cardiovascular disease and erectile dysfunction, especially because both conditions share common risk factors such as diabetes mellitus, hypertension, smoking, hyperlipidemia, and a sedentary lifestyle. Recent studies suggest that erectile dysfunction could be considered a potential marker for underlying silent cardiac or vascular disease processes. Endothelial dysfunction seems to play a major role in both sexual dysfunction and heart disease. With the initiation in 1998 of vasoactive drugs such as the phosphodiesterase-5 inhibitors for the treatment of erectile dysfunction, the underlying vascular components of erectile dysfunction have become a more prominent focus of attention in the clinical and research setting. This review critically examines the background, pathophysiology, and mechanisms behind erectile dysfunction and its close correlation to cardiovascular disease.