Left ventricular thrombus is a common complication related to acute myocardial infarction. Removing this with an incision of the free wall of the left ventricle may cause fatal cardiac dysfunction or arrhythmias. Furthermore, performing incision and suture on the fragile myocardium of an acute myocardial infarction patient may cause serious bleeding complications. If there is a patient with left ventricular thrombus who needs thoracotomy for another reason, the case is attempted with the thought that if effective intraventricular visualization and manipulation can be done, fatalities caused by incision and suture may be reduced. For patients undergoing cardiopulmonary bypass, if intracardiac manipulation is required, an endoscope can be used, and given the potential complications after the incision and suturing of the infarcted tissue, the benefits are deemed sufficient.