Acquired left ventricular pseudoaneurysm is a rare disorder that occurs after acute myocardial infarction. Herein, we present a 55-year-old male patient with a unruptured pseudoaneurysm after acute myocardial infarction presenting with severe mitral regurgitation. After resection of the pseudoaneurysm sac, the defect of 5 cm located at the posterolateral aspect of the left ventricle was repaired with a pericardium patch, and it was determined that mitral regurgitation diminished after cardiac geometry was restored and intervention to the mitral valve not required.