Renal artery stenosis (RAS) is a common manifestation of generalized atherosclerosis, frequently involving other vascular districts, particularly the coronary tree. Duplex ultrasonography is the diagnostic procedure of choice for screening outpatients for RAS. We report a case of metabolic syndrome in a 63-year-old obese man with atherosclerosis and low-grade RAS that was an important sign of cardiovascular risk. In fact, cardioscintigraphy and coronary arteriography showed severe coronary artery disease. RAS is an independent predictor of adverse cardiovascular events such as myocardial infarction, stroke, and cardiovascular death. In this case, duplex ultrasonography demonstrated the importance of screening for RAS as the expression of coronary artery disease.