We reexamined 21 patients with congenital pseudarthrosis of the leg (congenital pseudoarthrosis of the tibia; CPT) associated with neurofibromatosis-1 (NF-1), > or =2 years after the termination of treatment, for a statistical study of the results obtained by using Ilizarov's external fixator. Of the 21 tibias operated on, 17 consolidated after the first treatment, whereas four did not. Of the 17 consolidated tibias, four refractured and were retreated by using a variety of methods. Only one healed. At follow-up, which occurred > or =2 years after the removal of the fixator, the results were nine consolidations without deformities or with shortening <2 cm, five consolidations with axial deviation, and seven nonconsolidations. The statistically significant results were that (a) patients who were aged 5 years or older at operation had better results, and (b) the assembly II (resection of CPT stumps and their short-term compression possibly associated with corticotomy or epiphyseal distraction to correct limb discrepancy) gave better final results compared with the other device assemblies. We conclude that treatment with Ilizarov's fixator allows (a) a good percentage of healing over time (66.7%), especially in cases of normotrophic and cystic CPT; (b) further operations with or without the fixator to correct secondary or residual axial deviation; and (c) correction of limb discrepancy. This treatment avoids risking injury to the healthy contralateral leg. Additionally, for treatments that do not achieve satisfactory results, other treatment methods are not excluded. The CPT still remains a difficult problem for the orthopedic surgeon to solve.