The syndrome of lower-back pain associated with sciatic pain has probably been a problem since man first assumed the upright position. In 1937 Barr delineated herniation of the nucleu pulposus as a pathologic entity. Since that time, the standard surgical treatment has become laminectomy or laminectomy combined with fusion, with the emphasis on the disc between L4−5 and L5−Sl. Another mode of treatment was suggested when Smith and Brown” reported their clinical experience using intradiskal injection of chymopapain as the definite treatment of lumbar disk disease in 1967. In recent many years investigators in separate clinical studies showed that a benificial result can be achieved in a high percentage of patients treated by chymopapain injection. Our 29 patients who can be observed for more than 6 months after chemonucleolysis were clinically analysed. The results were as follows: 1. Of the 29 patients studied, 15 were males and 14 were females. 11 patients (37.9%) were in age between 41 and 50 years. 2. On clinical symptoms, 24 patients (82.8%) had radicular pain in the lower extremity. All patients had the limitation of the straight leg raising. 3. The most common level of herniated area was L4−5 disk as 22(75.9%) cases. In four cases (13.8 %) two levels of disks (L4−5 and L5−Sl) were involved. 4. On myelography the hour glass appearance was shown in 14 patients (49.3%).Complete block was found in 4 (13.8%) cases. 5. The increase of the straight leg raising was found within 3 weeks after chemonucleolysis in all cases. Motor power were recovered in 20 out of 22 cases and abnormal sensation were recovered in 17 out of 19 cases within 3 months after chemonucleolysis. 6. There were no correlation between persisting low back pain and narrowing of the disk space after chemonucleolysis, statistically. 7. In 23 out of 29 cases discometry test was positive. Among 23 cases, 21 cases recovered from their symptoms successfully after chemonucleolysis. 8. In chymo. R.A.S.T., 9 out of 15 cases were positive in 3 weeks after chemonucleolysis, and 12 out of 15 cases were positive in 3 months after chemonucleolysis.