Purpose: The purpose of this study was to evaluate the effectiveness of limb reconstruction and functional recovery using vascularized fibular graft in the treatment of extensive bone defect of long bone caused by various diseases. Materials and Methods: From september 1995 to March 2005, 21 patients with segmental bone defects were managed with vascularized fibular graft: 13 males and 8 females, aged 39 years on average (range, $8{sim}65;years$). The reconstructed site was the humerus in 9 patients, the femur in 5, the tibia in 4 and the forearm bone in 3. The length of bone defect ranged from $8{sim}17;cm$. Results: Twenty grafts were successful. The mean period to obtain radiographic bone union was 5.7 months on average. Conclusion: Fibular grafts allow the use of a segment of diaphyseal bone and of sufficient length to reconstruct most skeletal defects of the long bone. The vascularized fibular graft is indicated in patients with intractable nonunions where conventional bone grafting has failed or large bone defects.