Methyl methacrylate was used for the stabilization or replacement of portions of the cervical spine in 24 patients who had instability or neurologic deficit secondary to unresectable primary or metastatic tumors. Vertebral body replacement was performed after anterior decompression in 10 patients. Posterior stabilization, with or without a decompressive laminectomy, was carried out in 14 patients. Seventeen of the 24 patients were symptomatically improved; none was made worse neurologically, and all but 4 were able to be mobilized by the third postoperative day. During the first month after surgery, 5 patients died from widespread metastatic disease. Although initial stabilization was achieved in all cases, there were four instances of late instability. There were no infections and no unusual tissue reactions to the methyl methacrylate.