Introduction. The treatment complexity and patients’ rehabilitation with an open comminuted femoral fracture, with an extensive bone defect, is due to an increased risk combination of developing infectious complications due to the wound openness, with the need to restore a significant volume of bone tissue, for the proximal and distal fragments of the femurconnection. Open extramedullary or intramedullary osteosynthesis of bone fragments using metal implants is impossible in such cases due to the lack of the required bone tissue volume necessary to restore the normal bone length.In cases of open reduction, immediately after injury, there is a high probability of developing soft tissue necrosis, infectious complications, inflammatory and purulent-septic processes, as a result of the negative effect of early reduction on the blood supply of an already severely damaged limb.Difficulties arise with maintaining the limb length. The article describes a patient treating experience with an open femur fracture with an extensive defect in bone tissue, using external fixation in the early period with delayed plasty defect with autologous bone. The aim is to demonstrate a successful treatment case of a patient with an open femur fracture with an extensive defect in bone tissue, while maintaining the limb length. Results and discussion. A 22 cm long fibula was taken, two fragments were formed and they were installed in pairs.The periosteum and muscle segments are preserved on the graft surface. It was performed femur perosseous osteosynthesis with a wire-rod apparatus with femur bone defect replacement of paired autologous bone.The limb function was restored satisfactorily, the anatomical segment length was preserved, all fixation structures were removed, and the limb did not contain foreign bodies. Conclusion.The various techniques and technical combination facilities, external fixation, autotransplantation according to the classical technique, made it possible to completely restore the injured limb, reduce the complicationsrisk, and obtain a good clinical result.