A 65-year-old man was readmitted to the hospital with deep-vein thrombophlebitis 3 weeks after suffering a small infarction. Two days after the patient was readmitted severe symptoms of cardiac failure developed. Transthoracic echocardiographic examination showed an unusual echo-free space adjacent to the lateral wall of the left atrium. No further diagnostic information could be obtained from precordial examinations. Single-plane transesophageal echocardiography demonstrated the presence of a ruptured aneurysm in the posterolateral wall of the left ventricle and a pseudoaneurysm, which was severely compressing the left atrial cavity. On color-flow Doppler examination a tear was detected in the wall of the left ventricular aneurysm close to the posterior atrioventricular sulcus. Pericardial adhesions because of coronary artery bypass grafting performed 10 years before may have contributed to the unusual location of this left ventricular pseudoaneurysm, complicated with left atrium tamponade after myocardial infarction.