This paper presents a long-term follow-up study of 984 patients operated on for a herniated lumbar disc between 1959 and 1991. It was possible to follow 98% of patients from the time of operation to the time of writing. The mean follow-up period was 10.8 years. The most common presenting complaint was back pain with sciatica in one leg; the most frequent neurological finding was impaired straight-leg raising. Myelography confirmed the diagnosis in 80% of patients, but more recently enhanced computerized tomography and magnetic resonance imaging have been the preferred studies. The operative procedure was either hemilaminectomy or laminectomy with x 3.5 magnification and fiberoptic lighting. Herniated lumbar discs involved L4-5 and L5-S1 with equal frequency (47%). The recurrence rate was 6%, one-third of which developed during the 1st year after operation. The complication rate was 4%; there were no intraoperative vascular or intestinal injuries. The Prolo Functional Economic Outcome Rating Scale was used to measure long-term outcome and the results were compared to those of Pappas, et al. Patients who did sedentary work and housewives had statistically higher total and economic Prolo scores (p < 0.01) than those who did strenuous work. The majority of patients with the "failed-back syndrome" had pending legal or Workers' Compensation claims, or were at psychological risk for surgery. In 89% of patients the outcome was good--defined as a Prolo score of 8 in 10%, 9 in 19%, and 10 in 60%.