One of the most frequent outcomes after resection of bone tumors in children is a limb-length discrepancy. An intramedullary nail is a valid method for lengthening the limb. We report our experience with four cases of limb-length discrepancy in the lower limbs several years after the primary treatment of bone tumor resection and subsequent reconstruction. Two femoral PRECICE® nails (NuVasive, Inc., San Diego, CA) were introduced retrograde and two were introduced in an anterograde manner. All four cases healed and showed a reduction of the limb-length discrepancy, early loading, and complete bone osteogenesis. In one case, a reduction of the joint ROM recovered after release of the iliotibial band and a quadriceps release according to Judet's arthrolysis.