We performed 66 percutaneous lumbar nucleotomies (PLN) in 63 patients from October 1984 to March 1990. The patients (42 male patients, 21 female patients) ranged in age from 13 to 73 years (average, 36.8 years). Postoperative observation ranged from 6 months to 5 years and 11 months (average, 2.0 years). Pre- and postoperative discograms were reviewed. Fifty-one patients (79.7%) were judged to have successful results: They were able to return to gainful employment and to their preinjury level of activity. Six patients (9.4%) were judged to have unsuccessful results, and they required more radical surgical procedures. PLN was not effective for the patients with extremely severe positive SLR or agonizing leg pain.