The results of lumbar diskectomy for a sciatic syndrome in 90 patients were reviewed at an average of 8.5 years after operation. The best results were achieved in those patients who had their diskectomy within 12 months of the onset of their symptoms and through minimal approaches. Eighty-six percent of patients returned to gainful employment. Sixteen patients (18%) returned with low back pain attributable to the loss of intervertebral disk, of whom eight (9%) required secondary spinal fusion for control of pain. Seven of these latter patients obtained gratifying clinical and functional results. The findings suggest there is insufficient indication for routine spinal arthrodesis combined with lumbar disk excision. Those eight patients (9%) who developed a disabling postdiskectomy/postlaminectomy instability syndrome did so usually as a consequence of excessive bone and ligament excision and benefitted significantly from subsequent spinal arthrodesis.