The authors report the case of a 17 year old patient operated for valvular aortic stenosis associated with severe hypertrophy of the interventricular septum. The operation consisted of aortic valve replacement and septal myectomy. Color-flow imaging in the postoperative period showed a coronary artery--left ventricular fistula in the region of the septal myectomy. In view of the small size of the fistula on echocardiographic examination and the absence of a codified strategy of management of acquired coronary left ventricular fistula after surgery, a simple Doppler echocardiographic follow-up was proposed in this case.