The patient was an 85-year-old woman who developed chest pain on August 6, 1989, and was admitted to our hospital the next day. The diagnosis was acute inferior myocardial infarction. Her general condition was good at first; however, a harsh holosystolic murmur was suddenly heard 13 hours after the onset of infarction. Immediate cardiac catheterization revealed a ventricular septal perforation with a 2.2:1 shunt and total occlusion of the posterior descending artery. IABP was started 3 days after the onset of perforation. PCWP and shunt ratio decreased after starting IAPB; however, lung congestion continued to worsen. An emergency operation was performed on the 5th day after the onset of perforation. The post-operative course was uneventful. She is presently doing well 17 months after the surgery. Seven patients more than 80 years old have been surgically treated for postinfarction ventricular septal perforation in Japan and this patient is the oldest.