Metastatic malignant lesions involving the spine occasionally cause severe enough vertebral-body collapse to result in either spinal instability or neural compression, or both. Conventional decompressive laminectomy in such cases rarely results in neural improvement. It may, however, cause local instability of the spine, leading to a progressive kyphotic deformity and an increasing neural deficit. Anterior decompression allows excision of the focus of tumor and direct neural decompression. However, anterior stabilization by bone grafts usually does not succeed, as postoperative irradiation in dosages sufficient for tumor control may interfere with incorporation of the graft. Over a four and one-half-year period, fourteen patients with spinal instability secondary to metastatic pathological fractures of one or more vertebrae received anterior stabilization by replacement of the affected vertebral bodies with methylmethacrylate polymerized in situ. No postoperative external support was required, and the acrylic fixation achieved by this method was not affected adversely by subsequent irradiation averaging 4375 rads. There was only one soft-tissue infection, which did not involve the anterior stabilization. Twelve patients had major neural impairment preoperatively and required spinal cord or nerve-root decompression anteriorly prior to fixation. Nine had complete neural recovery postoperatively, two others were improved significantly, and one remained unchanged. None deteriorated neurologically. Five patients had undergone decompressive laminectomy before the anterior stabilization was attempted. None had improved neurologically, and all had increased spinal instability. There was one failure of fixation. The remaining thirteen patients had excellent relief of pain and restoration of spinal stability which did not deteriorate during the follow-up period, ranging from thirteen to forty-five months postoperatively.