OBJECTIVE: Minimally invasive percutaneous spinal procedures are popular in trying to reduce spinal pain. The aim of this paper is to evaluate the safety of intervertebral disc chemonucleolysis and to report the effectiveness of a percutaneous, minimally invasive treatment for contained herniated intervertebral discs in the lumbar spine using the recently marketed radiopaque gelified ethanol. METHODS: Pain relief before and after the procedure was self-evaluated by each patient using a verbal numeric scale (VNS) ranging from 0 to 10. Patients were also scored prior to procedure and after chemonucleolysis during several follow-up periods using the Roland-Morris low back pain and disability questionnaire (RMQ). Follow-up periods were defined as 0-6, 6-12, 12-18, 18-24, and 24-30 months. Clinically significant functional improvement (CSFI) was defined as a decrease of five or more points on the RMQ scale and a decrease of at least 50% of pain intensity using VNS. RESULTS: Using the RMQ scale, CSFI was achieved in 20/29 patients in the first follow-up period, 20/27 patients in the second follow-up period, 9/12 patients in the third follow-up period, 8/9 patients in the fourth follow-up period, and 4/4 patients in the last follow-up period. Using the VNS rating, CSFI was accomplished in 19/29 patients in the first follow-up period, 19/27 patients in the second follow-up period, 9/12 patients in the third follow-up period, 8/9 patients in the fourth follow-up period, and 4/4 in the last follow-up period. CONCLUSIONS: Intradiscal application of gelified ethanol may be effective in pain reduction using the VNS and Roland-Morris low back pain and disability questionnaire. The treatment is safe and easy to handle.