Left ventricle wall rupture is a feared complication in mitral valve surgery. We report a combined mitral valve anuloplasty and coronary artery bypass grafting procedure with severe, life-threatening bleeding complication due to left ventricular posterior wall rupture. The patient was successfully treated with a temporary left ventricular assist device to decompress the left ventricle in an attempt to minimize the bleeding, as the patient's condition did not allow standard repair of the left ventricle.