A successful operation on an infant with a tunnel through which the aorta communicated with the right ventricle is reported. The diagnosis was suspected preoperatively on the basis of two-dimensional Doppler color echocardiography and confirmed by cardiac catheterization. The aortico–right ventricular tunnel originated independently from the left coronary ostium and above the sinus of Valsalva. Patch closure from inside the tunnel under deep hypothermia was successfully performed. Follow-up is satisfactory 5 years later.