Objectives: The purpose of the present study was to assess long-term crestal bone level changes in avascular fibula bone grafts of the severely atrophied maxilla and mandible. It was also considered whether this treatment results in adequate reconstruction and successful long-term functional rehabilitation of edentulous patients with severely atrophied jaws. Methods: This retrospective study included 6 patients with a mean observation period of 8,7 years (5-12 years). All patients presented a Class VI atrophy according to the Cawood classification. Grafting and implantation were performed simultaneously or in a second procedure. A total of 26 implants were placed (8 Camlog implants and 18 Sterioss). Postoperative evaluation included clinical and radiographic examinations which were conducted by two different evaluators to standardize the judgment. Clinical criteria included implant success and crestal bone resorption. The radiographic evaluation aimed to quantify the resorptive changes and the measurements were performed using panoramic radiographs. Histologic specimens (Azur II and Pararosanilin staining) were obtained from a patient after 10 years with a trephine bur for the auxiliary placement of an implant. Results: 6 patients received subperiosteal onlay augmentation with avascular corticocancellous fibula bone grafts. The grafting procedure was successfully performed in all patients and no regrafting was necessary. All implants were integrated, but one implant was lost 2 years after the abutment connection. All other implants fulfilled the Buser criteria, thus rendering to a success rate of 97%. The maximum bone resorption of 8 % (±2,7%) after 12 years with values ranging from 1,4 to 2,4 mm was independent of the region (maxilla or mandible) and independent of the implant system. Histologic evaluation of the augmented fibula bone revealed a completely vascularized cortical bone with 95% of bone. Conclusions: In this clinical and radiographic evaluation, it was found that nonvascular fibula graft shows a long-term stable crestal peri-implant bone level. Keywords: fibula bone grafts, implants, atrophy, alveolar bone