The authors report the case of postero-lateral myocardial infarction complicated by free wall rupture at the 48th hour. The diagnosis was suspected clinically and transoesophageal echocardiography showed the appearance of pericardial effusion in a patient difficult to examine by conventional echocardiography. Transoesophageal echocardiography was performed and well tolerated. The transgastric view showed a thrombus adjacent to a thinned and lacerated postero-lateral wall. The clinical outcome was favourable after surgical repair.