Introduction : Right atrial (RA) and right ventricular (RV) dilatation that are associated with severe tricuspid regurgitation, and severe high RV pressure that is associated with pulmonary atresia and intact ventricular septum cause left ventricular (LV) dysfunction and hypoplastic lung. We have applied a modified RV obliteration technique that excludes non-functional enlarged RV for these diseases. Objectives : To evaluate the efficacy of our procedure. Methods and Results : Five patients (six operations) underwent the procedure without complications. Cardiothoracic ratio significantly decreased from 71±10% to 61±5% (p=0.017), and fractional shortening ended to increase from 27±17% to 37±5% (p=0.071). All of them achieved Fontan completion finally. One patient who underwent this procedure as a neonate experienced RV re-dilation 19 months later. He additionally received the same procedure in a Fontan operation, and then RV reduced again and good LV function was maintained. Conclusion : The application of modified RV obliteration technique is effective for Fontan candidates with nonfunctional RV.