An 84-year-old woman, who had undergone ligation for a coronary pulmonary artery fistula, coronary aneurysmectomy, and coronary artery bypass grafting at the age of 76 years, was referred to another hospital for chest pain and diagnosed with acute myocardial infarction based on coronary angiography results. The day after admission, she was transferred to our hospital after her blood pressure decreased and echocardiography showed left ventricular rupture. The Impella CP was introduced on the same day, and the surgery was performed on day 8 after one week of heart failure management. Intraoperative findings revealed a ruptured site in the lateral wall, which was repaired by patch closure. The patient was transferred for rehabilitation on postoperative day 24. As the patient was elderly with multiple organ failure and at high operative risk, a preoperative period to allow remodeling of the infarcted myocardium was considered crucial for a successful repair procedure. The left ventricle was decompressed using the Impella system to prevent enlargement of the rupture site in this case, and a 7-day preoperative optimization period was sufficient for improving myocardial damage. Thus, preoperative Impella-assisted management for left ventricular rupture might be effective in cases of free wall rupture after cardiac surgery with stable hemodynamic status as in the present case or oozing rupture.