A 2-year-old boy was admitted to our service with a diagnosis of double-outlet right ventricle (DORV) complicated by mitral valve stenosis. On echocardiographic measurement, the mitral annulus was 11mm (69% of normal) in diameter and 1.67cm²/m² in annular area. He underwent intraventricular tunnel repair and patch reconstruction of the right ventricular outflow tract under cardiopulmonary bypass. No attempt was made to operate on the mitral valve. DORV with mitral stenosis is a rare cardiac anomaly, the last 20 years only 21 cases have been reported, of which only 4 were cases with hypoplastic mitral rings. Although the patient made an uneventful recovery and remains well 5 months after surgery, a close observation is required for the mitral valve stenosis.