The authors report two cases of fissures of a left ventricular aneurysm diagnosed on the 8th and 21st days following an anterior myocardial infarction. In both cases, the clinical presentation consisted of a new episode of pain associated with a low cardiac output syndrome and adiastole. The diagnosis was confirmed by the simultaneous discovery of a pericardial effusion and a left ventricular aneurysm on echocardiography and cardiac catheterisation. An emergency operation, with circulatory assistance by means of intra-aortic counter-pressure, was performed and the infarcted area was excised. The post-operative course was uncomplicated in one case, but the other patient developed a false aneurysm of the left ventricle, requiring a second operation. The long term results were excellent with a follow-up of 30 months and 12 months respectively.