We experienced the case of a left ventricular-free wall rupture (LVFWR) following successful coronary intervention for acute myocardial infarction (AMI). A 73-year-old woman was hospitalized because of chest oppression that had been continuing for 8 days. She was diagnosed to have AMI, and percutaneous coronary intervention (PCI) was performed. PCI was successful. However, immediately following PCI, she developed electromechanical dissociation secondary to tamponade because of blow-out-type LVFWR. The perforation tear was initially closed by a direct suture, followed by reinforcement using bovine pericardium patches sealed with GRF glue. The patient died of irreversible brain damage on postoperative day 3, but no re-bleeding or aneurysmal dilatation was detected at autopsy.