OBJECTIVE: To determine the relationship between the clinical outcome and the extent of surgical laminectomy for adequate decompression on the cases of cauda equina syndrome, the authors review and analyze their cases and compared with those of literatures. METHODS: The authors reviewed 655 patients retrospectively who had underwent surgery on the cases of lumbar disc herniation from January 2000 to December 2004. There were 19 patients (2.9%) who presented for clinical cauda equina syndrome. Among them, we selected and analyzed 15 patients who were treated by unilateral partial hemilaminectomy with discectomy or bilateral partial laminectomy with discectomy, and they had been followed from 5 weeks to 47 months postoperatively (mean, 13.47 months). The levels of the disc herniations were L4-5 in 8 patients, following L5-S1 in 4 patients and 2 levels(L4-5 and L5-S1) in 3 patients. Motor and sensory recoveries were recorded. Postoperative urinary function recovery was defined according to Gleave and Macfarlane7). RESULTS: In 12 months postoperatively, the bladder function was obtained in 14 of 15 patients(93%) with regaining urinary continence. Thirteen of 15 patients(86%) with preoperative motor weakness of lower extremities were recovered. Sensory deficit of lower extremities, perianal and saddle anesthesia were all recovered. Patients had recovered on lumbosciatic pain and saddle hypesthesia, in turn, motor function and urinary incontinence. CONCLUSION: In treating cauda equina syndrome, the authors did less extensive surgery, such as unilateral partial hemilaminectomy with discectomy or bilateral partial laminectomy with discectomy for adequate decompression. The outcome is satisfactory and comparable with those of subtotal or total laminectomy.