Calcification of porcine heterograft valves may be greater in the pediatric than in the adult population. This multicenter study evaluates the long-term actuarially determined durability of porcine valves in children less than 21 years old. We evaluated 227 late survivors of porcine valve implantation with 47 aortic valves, 67 mitral valves, 14 tricuspid valves, 14 pulmonary valves, 77 pulmonary conduits, and 8 apicoaortic conduits. In this series, 20 porcine valves degenerated, most in the aortic and mitral positions. At 5 years 40% of aortic, 40% of mitral, 100% of tricuspid, 100% of pulmonary, and 89% of pulmonary conduits remained functional. In this series, calcification and dysfunction occurred significantly faster (p less than 0.05) in younger compared with older children and in left-sided or systemic positions (aortic and mitral) compared with right-sided positions (tricuspid, pulmonary, and pulmonary conduit).