Resection of a segment of mandible, particularly when associated with malignant disease, carries a high morbidity and mortality. Traditional methods of autogenous bone grafting have proved unreliable in immediate reconstruction of such mandibular defects because of the variability of the recipient bed. These unfavorable conditions for bone graft survival can be largely overcome using vascularized bone and vascularized soft tissue reconstruction. The radial forearm free flap has proved a versatile and useful method in intraoral reconstruction and can be used together with a segment of radius as a composite flap. The technique of raising a segment of vascularized radius is described and its use in immediate reconstruction of the mandible at the time of resection illustrated in a series of 14 consecutive cases. There was one microvascular failure in this series and one postoperative death. The remaining 12 cases have had a successful outcome and show clinical union in the follow‐up period varying from 11‐36 months. There is evidence indicating that the bone maintains its viability even in the presence of preoperative or early postoperative radiotherapy.