A 46-year-old man who developed fever and general fatigue was referred to our hospital with suspicion of infective endocarditis. A ventricular septal defect had been previously diagnosed. Transthoracic echocardiography revealed vegetation on the aortic, mitral, and pulmonary valves, and each valve had significant regurgitation. An emergency operation was performed because of congestive heart failure. The aortic and mitral valves were replaced with mechanical valves. The pulmonary valve was repaired ; the anterior leaflet was resected and replaced by glutaraldehyde-treated autologous pericardium. The patient's postoperative course was uneventful. Recurrence of infection was not observed for 3 years after the operation. Triple-valve endocarditis, especially that involving a combination of the aortic, mitral, and pulmonary valves, is rare. Involvement of multiple valves on both sides of the heart may be attributed to a congenital intracardiac shunt. Early surgical intervention may be useful to control infection and heart failure, as in the present case.