STUDY DESIGN: A retrospective analysis of the patients who had cauda equina syndrome caused by a herniated lumbar disc. OBJECTIVES: To assess the clinical debates concerning the diagnosis, treatment, and results of treatment. SUMMARY OF LITERATURE REVIEW: This syndrome has been considered as an absolute indication of surgical treatment in the herniated lumbar disc and poor prognosis after surgery were reported. Although there are debates on the timing of surgery, early recognition early surgical treatment are recommended for a better results of treatment. MATERIALS AND METHODS: 23 consecutive patients having a cauda equina syndrome caused by herniated lumbar disc were reviewed retrospectively. They were 14 males and 9 females having ages of 41.6 in average. The incidence of this syndrome was 3.8% of the patients who had surgical treatment of herniated lumbar disc. RESULTS: All patients had bladder dysfunction in addition to the low back pain and radicular pain in the leg, but five patient did not recognize their urinary retention which were shaded by severe leg pain. A surgical treatment were performed for all patients at 6.8 days in average after onset of the bladder dysfunction. At follow-up of 3 years and 3 months in average after surgery, 20 patients(86.9%) had satisfactory resolution of the low back pain and leg pain, and all patients had complete recovery of motor weakness except one patients who had residual foot drop. Bladder function recovered satisfactorily in 18 patients (78.3%), but 4 patients had some difficulty of urination and one patient needed a sphinterotomy for urination. CONCLUSIONS: The cauda equine syndrome in herniated lumbar disc was often not recognized early and a poor result of treatment was not rare, particularly in the patients who had acute onset and severe bladder dysfunction. So, early diagnosis and active surgical treatment are recommended for a better results of treatment.