Posterior left ventricular rupture (LVR) is a serious complication following mitral valve replacement (MVR), especially if occurring postoperatively with the chest already closed or the patient in the intensive care unit. Only one of the patients with this delayed type of LVR reported earlier has been treated successfully. Our experience consists of 4 such complications among 161 MVR patients, the incidence being 2.5%. Two of these patients survived. Mechanical factors seem to constitute the most important etiologic causes for this complication. Immediate reoperation must be performed, and extracorporeal circulation is generally mandatory for successful repair. The reconstruction of the ruptured posterior left ventricular wall in both surviving patients was performed from the epicardial surface of the heart using pledget sutures. The auricle of the left atrium was used to cover the site of the tear when bleeding was not stopped with pledget sutures. It usually seems possible to avoid this complication if all mechanical etiologic factors are taken into consideration. After successful correction, a pseudoaneurysm may arise and, for that reason, a cardiac echo sonography follow-up is recommended.