Periosteal radial forearm free flaps allow functional and curative treatment of osteoradionecrotic jaw lesions. The flap responds physiologically to hypoxia, hypocellularity, and hypovascularity, which are characteristic results of osteoradionecrotic injury. Here, we propose a reproducible, simple, and safe method for harvesting a forearm free flap, allowing us to obtain a periosteal composite free flap. Our technique offers potential early management of osteoradionecrotic lesions resistant to medical treatment. Furthermore, the forearm periosteal composite free flap offers the advantage of a long vascular pedicle which is ideally suited for necks which have been submitted to irradiation or multiple operations. Thusly, vascular anastomosis can be performed at a distance from the irradiated areas. Compared to other periosteal free flaps, such as those harvested from the iliac crest or the internal femoral condyle, the presence of a skin paddle facilitates clinical flap monitoring, optimizes the restoration of bone sealing, and facilitates the treatment of scarring.