A follow-up evaluation of 357 patients injected with chymopapain ten to 20 years earlier included 97 females of mean age 42.2 years and 260 males of mean age 41.6 years. Pain distribution and physical findings were positive for discogenic involvement of long duration prior to chemonucleolysis. Eighteen patients were treated under worker's compensation. Postoperation, significant back pain persisted less than 24 hours in seven patients, less than six days in 133, less than 21 days in 178, from one to three months in nine, and between three and six months in two patients. Leg pain remained less than 24 hours in 32 patients, between one and five days in 212, between six and 21 days in 96, between one and three months in seven, and between six and 12 months in three patients. Similar improvement in extensor hallucis longus weakness and straight leg raising was also noted. Pain relief in the long term showed none persisting in the 158 patients or 44%, mild remaining pain in 107 or 30%, moderate pain in 71 or 20% and some pain in 21 or 6%. Thus the result was graded satisfactory in 74%. Complications included thrombophlebitis in two, pulmonary emboli in two, severe abdominal stress two days postoperation in one, severe anaphylatic reaction in one, and transient chest pain of undetermined etiology in one patient. All made good recovery from these complications.