The exercise hemodynamics of eight patients who underwent cardiac catheterization were assessed at rest and during exercise, before and after left ventricular aneurysmectomy by the classical technique. Left ventricular end-diastolic volume increased before operation and then significantly decreased after the operation (p < 0.05). The ejection fraction increased from 0.27 before the operation to 0.46 after the operation (p < 0.01). The cardiac index, which was low before operation, increased within the normal range after operation. Mean systolic circumferential tension also decreased significantly (p < 0.01) after the operation. Thus, the indexes at rest showed improvement. Left ventricular end-diastolic pressure showed a decreasing tendency after the operation both at rest and during exercise in comparison with that before the operation. However, the difference was not significant. The stroke work index increased significantly during exercise after the operation (p < 0.05). Before the operation, the stroke work index did not increase despite the elevation of left ventricular end-diastolic pressure; however, after the operation, the stroke work index increased during exercise without much increase of left ventricular end-diastolic pressure. This indicated improvement in the Frank-Starling curve and recovery of preload reserve by the resection of the left ventricular aneurysm. Thus, an important factor for demonstrating improvement in postoperative cardiac function was clarified through its relation to exercise load.