Chemonucleolysis is a significant innovation in the treatment of herniated lumbar disc disease. The prodedure is relatively safe and the results are highly acceptable, but in most studies, the failure rate is 20-25%. Computed tomography was performed from January, 1986 to June, 1987 at the Department of Orthopedic Surgery, Yonsei University on six patients with herniated lumbar discs who did not improve with chemonucleolysis. The results of this study are as follows : 1. The herniated lumbar disc remained unchanged in 4 cases and was reduced in 2 cases. 2. In 2 cases of hernia reduced, the development of a diffuse annular bulging was noted and compression of the dural sac unchanged. 3. Chemonucleolysis was carried out at two levels in 2 cases and the herniated lumbar disc was not changed in these cases. 4. Thickening of the ligament flavum was noted in 1 cases. 5. Computed tomography findings after chemonucleolysis were good correlation with the clinical results in failed cases. In the cases not relieved the symptoms over 3–6 months after chemonucleolysis, it is necessary follow up computed tomography to decide the further treatment.