A 60-year-old diabetic women with acute inferior myocardial infarction was admitted to our hospital. An echocardiogram suggested a left ventricular false aneurysm. A left ventricular cineangiogram showed the communication between the left ventricle and the right ventricle through a false aneurysm. At operation one week after the infarction, the pericardial space was free from adhesions. A pseudo-false aneurysm communicating to both ventricle was revealed. The defects were closed with patches and pledgetted mattress sutures. The pseudo-false aneurysm was obliterated with pledgetted mattress and running sutures. The postoperative course was uneventful and the patient was discharged without complication. We emphasize the importance of preoperative morphological and hemodynamic evaluation using a left ventricular cineangiogram in the case of post-myocardial infarction ventricular septal perforation.