The conservative treatment of neoplasms of the locomotor apparatus means the production of bone defects that may be filled with prostheses, bone grafts, systems of osteosynthesis. In the vertebral column, reconstruction of the resected elements--in the case of total vertebrectomy--requires the combination of anterior and posterior implants. It is the purpose of this study to analyze a group of 42 patients who, after accurate and uniform oncological (Enneking) and surgical (Weinstein-Boriani-Biagini) staging, were submitted to excision of one or more vertebral bodies for the treatment of neoplastic pathology, with reconstruction by prosthetic carbon fiber modular implant in order to obtain immediate stability, and to stimulate solid intervertebral fusion by bone grafts introduced inside the prosthesis. Thirty of the 42 patients presented with primary malignant tumor, 3 with benign tumor, 6 with solitary metastases, and 3 with plasmacytoma. In 32 cases, en bloc resection of the vertebral body was carried out (vertebrectomy) with combined anterior and posterior access in 29 patients (69.0%), and by posterior approach alone in 3 cases (7.1%). Ten intralesional corporectomies were carried out, 8 by anterior approach, 2 by posterior approach. The carbon prosthesis was filled with cortical and cancellous bone grafts in 38 cases. At a mean clinical and instrumental follow-up obtained 26 months after surgery for all of the patients, the use of a carbon prosthesis did not cause short- or long-term mechanical complications. The results of our study tend to affirm that the use of a carbon fiber modular implant may fill any loss of bone substance of the vertebral column, that it allows for immediate weight-bearing, and that if favors bone fusion. Some particular features of the carbon prosthesis favorably adapt to the surgical method of vertebrectomy: 1. The various components of the prosthesis may adapt to any type of bone resection of the vertebral body, even in unexpected situations; 2. Connection to posterior instrumentation in total vertebrectomies avoids the use of an anterior plate, thus reducing the time required for reconstruction of the anterior column, eliminating necessary surgical procedures in the segmental vascular structures. Finally, the radiolucency of the prosthesis allows for an easy evaluation of the formation of bone within and around the implant up to definitive anterior fusion and, of no less importance, early diagnosis of any local recurrence.