Thirty-one patients with spinal tumors underwent reconstructive surgery with our spinal instrumentation system (MPDS and MADS), with or without our new vertebral tumor prosthesis. The characteristics of the spinal tumors were analysed statistically and the treatment outcome was evaluated. There were 4 benign tumors, 6 malignant tumors, and 21 metastatic tumors. The malignant tumors involved the sacrum more frequently than the benign tumors (p=0.0098). Metastatic tumors involved the thoracic spine more frequently than benign or malignant tumors (p=0.0161). The average number of affected vertebrae was 1.2 in the benign tumors, 1.8 in the malignant tumors, and 2.4 in the metastatic tumors. The metastatic tumors had a tendency to involve the anterior or middle part of the spine more frequently than the benign or malignant tumors (statistically not significant). After surgery, neurological improvement was noted in 8 patients, nochange in 19 patients, and impairment due to resection of the nerve roots in sacral tumors in 4 patients.