Metabolic syndrome is a complex of symptoms that include obesity, insulin resistance, hypertension and dyslipidemia. Obesity, diabetes and other cardiovascular risk factors are closely associated with erectile dysfunction(ED), and endothelial dysfunction with reduction of nitric oxide activity is the basis of the correlation between metabolic syndrome and ED. Cardiovascular risk factors are predictors of ED in patients with metabolic syndrome, suggesting that prevention of metabolic syndrome may benefit sexual function. ED can also be a sentinel event for cardiovascular disease. Clinically ED is very closely associated with diabetes, obesity, dyslipidemia and chronic inflammation. Weight control and lifestyle changes, such as increasing physical activity and stopping smoking, can reduce the prevalence of metabolic syndrome and ED.