The radiofrequency ablation effect was observed in 21 patients with single right atrioventricular accessory pathway by superior vena cava approach. Because of many factors, radiofrequency ablation by routine inferior vena cava approach failed. However, all of these accessory pathways were successfully ablated by the superior vena cava approach with could significantly reduce operation and radiofrequency ablation time and exposed time in x-ray, and there were not any complications. The success was probably related to the good contact between the ablation catheter tip and ablation target point. It is suggested that radiofrequency ablation of right atrioventricular accessory pathways by superior vena cava approach is effective and safe when the routine inferior vena cava approach is difficult or unsuccessful.