Backache and severe leg pain, associated with spondylolisthesis, can be relieved by surgical methods, as shown by the eighteen cases presented. The technique of operation is concerned with two principal problems: first, stabilization of the weak link in the spinal column to relieve tension and strain on the associated muscles and ligaments and to prevent further progression of the subluxation; and, second, relief of the nerve-root oppression responsible for the sciatic pain. Nerve-root pressure was accounted for by a protruded intervertebral disc in only one of the nine cases of sciatica; the remaining eight patients were relieved of pain when the involved intervertebral foramina were unroofed. The operative technique which appears to offer the greatest permanent benefit and the most dramatic relief of pain is a combination of laminectomy, intervertebral for laminoctomy, and chip fusion.