Fistulas between the aorta and left atrium, invariably a complication of aortic valvular endocarditis, are rare and infrequently diagnosed premortem. We describe a patient who presented with this entity and review the reports of five other patients for whom a diagnosis was made premortem. A number of causative organisms have been identified. The clinical course is characteristically one of rapidly progressive heart failure. Notably, only half of these fistulas were detected by transthoracic echocardiography, whereas all were identified by transesophageal echocardiography when utilized. Once the diagnosis is made, prompt surgical repair is required to avert the high mortality from rapidly developing refractory congestive heart failure.