Steffee operation is a surgical method of internal fixation for unstable conditions of the spine. Up to March 1991, 32 cases of various spine disorders were treated with the Steffee system in our hospital. These operations brought good results, as 83.4% of the cases received either good or excellent functional and clinical ratings postoperatively. Among patients with spondylolisthesis, the degree of slip correction averaged 58.5% postoperatively. Neurological complications are avoided by accurate localization of the screws.