Objective : To investigate the surgical outcomes of left ventricular free wall rupture (LVFWR) and ventricular septal perforation (VSP) in terms of mechanical complications following acute myocardial infarction (AMI). Methods : Subjects comprised 26 patients (male : 12, female : 14, mean age : 74 years) who underwent surgery between 2001 and 2012. The LVFWR type was blowout in 2 cases and oozing in 5 cases. Immediately after diagnosis, 4 cases underwent intra-aortic balloon pumping (IABP) and 2 cases received extracorporeal membrane oxygenation (ECMO). LVFWR was repaired by suture and patch closure in 5 patients and by TachoComb in 2 patients. VSP was caused by anterior infarction in 15 cases and inferior infarction in 5 cases. IABP was inserted in 16 cases. VSP was repaired by the infarct exclusion technique in 17 patients, while 2 patients underwent suture or patch closure. Results : The operative mortality rate was 14.3% for LVFWR and 15.8% for VSP. The cause of operative death in 1 patient with blowout type LVFWR who was in a state of cardiopulmonary arrest on arrival, was low cardiac output syndrome (LOS). The causes of operative death in VSP included 2 patients with LOS and 1 patient who died suddenly 8 days postoperatively due to ventricular fibrillation. Two VSP patients underwent repeat surgery for residual shunt. The five-year Kaplan-Meier survival rates were 85% for LVFWR and 62% for VSP. Of 20 patients who received IABP preoperatively, the time from confirming LVFWR or VSP diagnosis after admission to IABP initiation was 103±45 (48-120) min in the survival group (n=17) and 259±174 (122-455) min in the operative mortality group (n=3). A significant difference was observed between the two groups (p=0.04). Conclusion : Therapeutic strategies including rapid diagnosis after admission, early insertion of IABP, and prompt surgery could improve the prognosis for patients with LVFWR and VSP following AMI.