The combination of percutaneous manual and endoscopic Ho:YAG laser discectomy (PELD) is a new minimal intervention technique in treating patients with herniated lumbar discs that do not penetrate the posterior longitudinal ligament. The results in 100 patients treated with PELD were compared randomly with those in 100 patients treated by chemonucleolysis with chymopapain (CN) and 100 patients treated by automated percutaneous lumbar discectomy (APLD) at the same hospital. We followed the 300 patients postoperatively for 1 year, with physical examination, postoperative plain lumbosacral radiography, CT, MRI and a self-assessment questionnaire. Some 68% of the patients in the PELD group considered the outcome as excellent or good and 23% as fair; the corresponding figures were 55% and 27% in the CN group, and 48% and 32% in the APLD group. Nine percent of the patients in the PELD group underwent open microdiscectomy or were suffering from back pain with sciatica, compared with 18% in the CN group and 20% in the APLD group. PELD showed better extraction of the hernia mass than APLD and a lower rate of low back pain and less decrease in disc height than CN.