Most cases of spondylolisthesis are asymptomatic and successfully managed with conservative treatment. Operation was performed in 20% of symptomatic cases having severe back pain, neurological symptoms and/or progressive slipping. Although surgical treatments are divided into decompression and fusion, various methods were tried from simple Gill's resection to posterior and/or anterior fusion with instrumentation in case of severe slipping. The authors reviewed 54 cases of symptomatic spondylolisthesis, who were surgically treated, and had follow up evaluations our institution during past 6 years from March, 1990, to March, 1996. 1) The age distribution was from 19 to 64 years of age and the highest prevalent decade was at the 5th. 2) There were 14 male and 40 female patients with female preponderance about 3 to 1 ratio. 3) Thirty one cases were isthmic type and 23 cases were degenerative type. The ratio between isthmic type and degenerative type was about 2:1. 4) The displacement between L4 and L5 was 25 cases and the displacement between L5 and sacrum was 18 cases, and others were L3 and L4, L4 and sacrum, L5 and L6. 5) Overall results are excellent in 7 cases(13%), good 35 cases(65%), fair 10 cases(19%), and poor 2 cases(4%). 6) There were no changes in slipping in 23 cases(42.6%). Occurred in partial reduction were possible in 30 cases (55.5%), and further slipping developed was 1 case(1.9%).