Although long bone defects may be treated by callus distraction, frequent complications arise from the long duration of external fixation. To reduce such complications, bone transport over an intramedullary nail (BTON) has been done for tibial bone defect.In 12 patients (mean age, 46.1 years) of chronic osteomyelitis or bone defect, segmental transport was done using external fixator over an intramedullary nail. Prior to the index procedure, all patients had had serial debridements and five required myocutaneous or free flaps for covering of soft tissue defects. Using Mekhail's criteria, functional results were evaluated.The mean transported amount was 5.9 (range, 3.5-12) cm. The mean external fixation index was 26 days/cm, and healing index was 62.6 days/cm. The primary union of distraction and docking site was achieved in all, except for one failure in union at the docking site, which required another bone graft. Except for one patient with associated ankle injury, all had excellent or good functions. There was one recurrence of osteomyelitis and one procurvatum of the proximal tibia of 10 degrees .BTON may be a successful method in tibial reconstruction and allows patients to return to daily life earlier with relatively few complications.