We describe a case of a 67 year-old patient with obstructive coronary artery disease that, in the preoperative survey for inguinal herniorraphy surgery, discovered, by a two-dimensional echocardiogram, a tumor in left atrium, mobile, non-obstructive. The patient underwent a cineangiocoronariography showing severe stenosis in the left anterior descending artery, moderate stenosis in the left circumflex artery, near the origin of the first marginal branch, and a non-obstructive plaque in the right coronary artery. There was also moderate left ventricular dysfunction. After that, the patient has gone coronary artery bypass surgery and resection of the left atrial tumor. The histological exam revealed that the tumor was, in fact, a myxoma.