Degenerative lumbar spondylolisthesis requires fusion of the involved segments and decompression laminectomy because it is mechanically unstahle and usually associated with stenosis of the spinal canal. Transabdominal retroperitoneal approach through small longitudinal pararectal skin incision provides easy and safe access to L3-4 and L4-5 disc spaces with less bleeding. We thought that anterior interbody fusion enable us to restore the disc space and to reduce partially the listhesis with less hleeding and less harvest of graft hone compared to posterolateral fusion, and also without the risk of neural or dural damage which could he occurred in posterior lumbar interbody fusion 4.15.16.17). Thus, authors performed the same-day anterior and posterior spinal surgery (APSS) in 28 patients (30 disc spaces) from 1992 to 1996 and analyzed the clinical and radiological results. The most common site of involvement was L4-5 level (82.1%). The mean follow-up period was 2 years and 2 months (from l2 months to 4 years). Fusion was ohtained at 29 disc spaces (96.7%) within 24 weeks (average, I 6 weeks). The anterior displacement was corrected up to the average of 65.4% (5.8mm) postoperatively and the average of 60.7% (5.2mm) correction remained at last follow-up. The intervertebral disc space was restored up to the average of 96.9% (7.5mm) postoperatively and the average of 86.0% (6.2mm) restoration remained at last follow-up. Twenty-five out of 28 patients (89.2%) showed excellent or good clinical results hy the criteria of Kim, et al6). In conclusion, the same-day procedure of successive anterior interbody fusion, decompression laminectomy and posterior pedicular instrumentation for the degenerative lumbar spondylolisthesis associated with spinal stenosis was thought to be a good method of treatment.