➤Bone lengthening has been used successfully for several congenital and acquired conditions in the pediatric clavicle, humerus, radius, ulna, and phalanges.➤Common indications for bone lengthening include achondroplasia, radial longitudinal deficiency, multiple hereditary exostosis, brachymetacarpia, symbrachydactyly, and posttraumatic and postinfectious growth arrest.➤Most authors prefer distraction rates of <1 mm/day for each bone in the upper extremity except the humerus, which can safely be lengthened by 1 mm/day.➤Most authors define success by the amount of radiographic bone lengthening, joint motion after lengthening, and subjective patient satisfaction rather than validated patient-related outcome measures.➤Bone lengthening of the upper extremity is associated with a high complication rate, with complications including pin-track infections, fixation device failure, nerve lesions, nonunion, fracture of regenerate bone, and joint dislocations.