This paper presents a technical description of the inlay technique performed with an allograft block in the reconstruction of a severely atrophic posterior mandible. It includes a histologic case series of five patients treated with the same grafting procedure and rehabilitated with dental implants 2 months after placement of the graft. The histologic analysis showed large amounts of newly formed bone in tight connection with the allograft and large marrow spaces with intense cellular activity and the presence of osteocytes. Allografts might serve as an alternative to autogenous and heterologous grafting in posterior mandible augmentation using the inlay technique.