Fourteen skeletally immature children with congenital pseudarthrosis of the tibia were treated by excision of the pseudarthrosis, double onlay autogenous cortical bone grafting, and intramedullary nailing. Union was achieved in 12 patients, and no refractures occurred at the site of the original pseudarthrosis. In three patients, a fresh pseudarthrosis developed at a different site; these united after repeat onlay grafting. Five skeletally mature patients were treated by excision of the pseudarthrosis, compression at the site, and limb lengthening by callotasis. Union was achieved in three. Gain in tibial length ranged from 6 to 13 cm, with no significant complications during lengthening. The authors conclude that union can be achieved and refractures prevented in a significant proportion of skeletally immature children with congenital pseudarthrosis of the tibia by excision of the pseudarthrosis, dual onlay bone grafting, and intramedullary nailing. Any residual shortening of the limb can be treated at skeletal maturity.