From January 1982 to December 1994, 432 patients with tetralogy of Fallot underwent the corrective operation. We extended the right ventricular outflow tract (RVOT) in 271 of the patients by using bovine pericardial patch treated by glutaraldehyde. The results were satisfactory. We emphasize that bovine pericardial patch is good material for extending RVOT, because it has many merits including high intensity, satisfied suture, no leakage, and abundant supply. Long-term follow up (maximum 12 years and 3 months) showed no ventricular aneurysm due to the degeneration of bovine pericardial patch.