The purpose of this study was to review both the anatomic and functional results of treatment of adolescent tibia vara with distraction osteogenesis by using the circular external-fixation device. Twelve tibias in eight patients were treated. Preoperative proximal tibial varus averaged 18 degrees (range, 7-26 degrees). Postoperatively the mean deviation from standard anatomic alignment of the proximal tibia was 2.5 degrees (range, 0-7 degrees). All patients were allowed to weight bear as tolerated throughout the 12 weeks of frame wear. Function was assessed by knee score and was improved in all patients at a mean follow-up of 23 months. There were no neurovascular complications or delayed unions. One patient required return to the operating room because of premature consolidation of his regenerate.