Azygos continuation is seen in 0.6% of patients with congenital heart disease. The major significance of this anomaly lies in its association with complex cardiac defects and the technical difficulty that can accompany cardiac catheterization. We report our experience with successful catheter ablation of a right posteroseptal concealed accessory pathway in a 6-year-old boy with infrahepatic interruption of the inferior vena cava and azygos continuation.