Aim: The aim of the study was to analyse the long-term follow-up of patients who were treated with chemonucleolysis for single level disc prolapse. Method: In our retrospective study we reviewed 112 cases that underwent chemonucleolysis for single level lumber disc herniation during the period of 1988–1996. Mean follow up was 9.5 years. In order to estimate the functional outcome of chemonucleolysis Oswestry Disability Index questionnaire was used. Results: An excellent or good response occurred in 79 patients (70.5%); 12 patients (10.7%) showed moderate response with minimal disability. Treatment failed in 21 patients (18.5%) who showed poor response and 12 of these 21 patients went for surgery within a mean period of 6 months. One patient had surgery at different level than chemonucleolysis. There was only one incident of procedure termination because of epidural contrast leak. There was no case of anaphylaxis or discitis. Conclusion: We conclude on the basis of our results that chemonucleolysis is a safe and effective treatment modality for lumber disc herniation in carefully selected patients.