A long-term prospective study of 100 patients undergoing lumbosacral discectomy was carried out in an attempt to delineate the natural history of these patients and to assess the relative significance of preoperative factors as determinants of long-term outcome. Neurological findings were documented preoperatively and at 1 month, 1 year, and 5 to 10 years postoperatively. A questionnaire using subjective and objective data was given to patients at 1 year and 5 to 10 years postoperatively. An 83% long-term follow-up result was obtained. At a minimum of 5 years postoperatively, 62% of patients had complete relief of back pain and 62% had complete relief of leg pain; 96% were pleased that they had submitted to surgery and 93% were able to return to work. Nine percent reported that their back pain at 5 to 10 years was as severe as or worse than preoperatively and 11% reported that their leg pain was as severe as or worse than preoperatively. The reoperation rate was 18%. Preoperative factors found to be significantly associated with outcome at 1 year postoperatively were not significantly associated with outcome at 5 to 10 years postoperatively. The results of lumbosacral discectomy appear favorable as evaluated in this study. Preoperative factors useful as predictors of short-term outcome are much less reliable when considering the long-term results.