With the purpose of clarifying the limits of resection surgery (en bloc excision) for the treatment of bone tumors of the spine, the authors report the indications and results of 43 operations. This series was homogeneous in terms of oncological and surgical staging, as well as with regard to surgical method used and anaesthesiology. Three different types of surgery were performed: en bloc resection of tumors of the body (sectors 5-9 or 4-8 depending on the WBB staging system), of the posterior arch (sectors 10-3) or characterized by eccentric growth (sectors 2-5 or 8-11). The surgical margins were histologically studied in all of the cases: based on the evaluation and on histological diagnosis further chemo- and/or radiation therapy were decided on. Long-term follow-up was obtained for all of the cases (from 6 to 153 months, mean 30 months; 26 cases followed for more than 24 months). Six of the patients died as a result of the disease from 10 to 28 months after resection. There were 4 local recurrences, 4 pulmonary metastases, and 5 metastatic disseminations to the skeleton and to other tissues observed in 11 patients. At final follow-up 33 patients (77%) were thus disease-free (32 continually), in excellent condition, and capable of living a normal life. Complications and treatment are also reported. A careful study of the neoplasm, an appropriate selection of the patients based on diagnosis and histological staging, a knowledge of the natural progression of bone neoplasms and of the surgical anatomy of the vertebral column, the application of suitable measures of anaesthesiological control, allow for a correct cost/benefit evaluation of this type of surgery as compared to oncological methods that are less effective but more diffused. On the basis of these considerations indications for en bloc resection in tumors of the spine are defined.