We present the case of an old patient with coronary artery disease and two previous myocardial infarctions, admitted to the hospital by syncopal episodes, in which the coronariographic study showed the ectopic origin of the left main coronary artery in the right sinus of Valsalva with anomalous course between the aortic and pulmonary arteries. In this case the initial coronariographic diagnosis and the therapeutical attitude (initially aggressive only in cases of interarterial course) was confirmed by mean of transesophageal echocardiography, showing a better topographical definition of the ectopic vessel aberrant course, although due to the high degree of left ventricular disfunction and the diffuse disease of distal vessels in this patient, CABG surgery was avoided. The angiographic feature is described and the transesophageal approach is remarked as a complementary diagnostic tool in the correct definition of the anomalous course.