Fifty patients, all of whom were sixteen years old or younger, underwent discectomy for a herniated lumbar disc at the Mayo Clinic between 1950 and 1976. Ninety-four per cent of the patients had had excellent or good initial relief of symptoms after the initial operation. Subsequently, however, twenty-eight of the thirty-seven patients who initially had undergone disc excision only required additional treatment for low-back pain or sciatica. Twelve of them required a second operation, consisting of nine discectomies (six with a concomitant spine fusion), two spine fusions alone, and one re-fusion. Of the thirty-seven patients who initially had had disc excision alone, three had a recurrent disc protrusion and five had a disc protrusion at another level. Of sixteen patients who had had multiple subtotal hemilaminectomies at the initial operation, either for involvement of multiple discs or for exploration, seven required reoperation. In the twelve patients who had had both a disc excision and a lumbar spine fusion as the initial operation, there were no recurrent disc protrusions and only one patient had a protrusion at another level. Follow-up on all patients ranged from five to thirty years (average, nineteen years). Ninety per cent of the patients stated that the condition of the back had little or no effect on their current way of life, despite the presence of continuing back complaints in some. However, we rated the results of the initial discectomy at follow-up as excellent or good in 73.5 per cent and poor in 26.5 per cent of the patients.