We report herein the case of a 42-year-old man who developed a left ventricular-right atrial communication and aneurysm of the mitral valve caused by infective endocarditis, which was associated with aortic regurgitation. Based on the findings of congestive heart failure, prolongation of the PR interval, and the added threat of rupture of the mitral aneurysm, surgical treatment was decided upon as the best course of action. The aortic and mitral valves were replaced with prosthetic mechanical valves, and the septal communication was simultaneously closed with a patch. The patient's postoperative course was uneventful and he has been in good health since. Thus, we believe that aggressive surgical intervention for complicated lesions such as those seen in our patient may be life-saving, even in the presence of inflammatory signs.