Twenty percutaneous rotational osteotomies, stabilized with interlock nails, were performed in the lower limbs of 15 skeletally mature adolescents with cerebral palsy to correct rotational deformities. The medical records and radiographs of those patients were retrospectively reviewed. Nineteen osteotomies (95%) in 15 patients healed without major complications. One patient had one tibia (5%) pseudarthrosis, which was successfully treated with additional fibular osteotomy and exchanging the nail. Excluding this case, the average healing time for the femoral and tibial osteotomies was 8 weeks, ranging from 7 to 9 and from 6 to 10 weeks, respectively. Casting was not required to add stability. Percutaneous rotational osteotomy with intramedullary nail fixation is a reliable and effective treatment option to correct rotational malalignment of the lower limb in skeletally mature patients with cerebral palsy.