Late results in the surgery for congenital heart disease repaired with external conduit have not yet been fully elucidated. We experienced a reoperation of tetralogy of Fallot (TF) that was previously repaired with an aortic homograft pretreated with beta-propiolactone for the reconstruction of right ventricular outflow tract. Ten years after correction of TF, right ventricular failure developed due to the regurgitation of tricuspid valve. At reoperation tricuspid annuloplasty was performed, and the valve of aortic homograft was also replaced with xenograft because of its uncertain durability. However, the resected valve had pliability with least degenerative change macroscopically. The postoperative course was smooth. The case was a rare one of late reoperation of TF due to the tricuspid valve regurgitation, and the case also indicated unexpected long durability of the valve cusp of the aortic homograft.