A young man had a congenital sinus of Valsalva aneurysm originating from the right coronary sinus, complicated by fistulas draining into both right atrium and right ventricle, as well as a congenitally abnormal aortic valve with mild aortic insufficiency. His dramatic clinical presentation, with the sudden appearance of severe biventricular cardiac failure unresponsive to intensive medical therapy, was an important clue to making the correct pre-operative diagnosis. The use of non-invasive techniques, such as phonocardiography and M-mode and two-dimensional echocardiography, is highlighted. Full cardiac catheterization was employed to define the cardiac pathophysiology. This was one of the few cases documented in which a catheter could be passed from the aorta into the right ventricle via the fistula connecting these two chambers. The fistulas were closed and the aortic valve replaced. Postoperative investigations confirmed the success of corrective surgery. As far as we are aware this is the first documented case of successful repair of a congenital sinus of Valsalva aneurysm rupturing into both the right atrium and right ventricle, accompanied by aortic insufficiency.