Endothelial dysfunction is an important process in the development of atherosclerotic cardiovascular disease, while it is also a major pathophysiological mechanism underlying vasculogenic erectile dysfunction (ED). Expectedly, these two prevalent disorders are linked also at the clinical level: ED is common in patients with overt and silent coronary artery disease, while ED is increasingly being regarded as the early clinical manifestation of a generalized vascular disease and carries an independent risk for future cardiovascular events. The emerging awareness of ED as a barometer for cardiovascular disease offers a unique opportunity to enhance preventive vascular health in men. Lifestyle and risk factor modification, as well as pharmacologic therapy (both phosphodiesterase type-5 inhibitors and non-ED-targeting drugs), appear to confer additional benefit both in terms of ED treatment and overall cardiovascular risk; this benefit may be related, at least partly, to the improvement of endothelial function and anti-inflammatory effects. The present review identifies pathophysiologic links between endothelial dysfunction, ED and coronary artery disease, presents methodological aspects regarding penile and systemic endothelial function, and discusses the clinical implications in terms of diagnosis of ED, assessment of patient risk, and treatment.