Dorsal column stimulation (DCS) was used in the treatment of chronic intractable pain in 51 patients. Twenty-five of the patients had back and leg pain secondary to the treatment of intervertebral disc disease; 11 had postoperative pain after general or thoracic surgical procedures. The remainder suffered pain related to multiple sclerosis, spinal cord injury, carcinoma, and peripheral vascular disease. Pain had been present for a mean of 24 months. Thirty-seven patients underwent DCS electrode placement by open laminectomy, and 11 had percutaneous epidural DCS electrode placement. Three patients first underwent epidural DCS electrode implantation and subsequently had DCS electrode implantation by laminectomy. No major complications were noted, although multiple lesser complications required 33 additional operative procedures for correction. Follow-up periods ranged from 12 to 67 months, with a mean of 38 months. Immediately after implantation. 47% of the patients reported that they had essentially complete pain relief, but 3 years later this had decreased to 8%. No patient followed for 4 years or longer reported complete pain relief. Thirty-three per cent of the patients discontinued the regular use of narcotics for pain relief after DCS electrode implantation. Unfortunately, only 16% were able to return to gainful employment or full physical activity after DCS. Based on these data and a review of the literature, the following conclusions are made: (a) assessment of success in the treatment of chronic pain is strongly dependent on the criteria used for patient evaluation: (b) with the criteria of this report, DCS is a relatively ineffective treatment for chronic pain; (c) epidural percutaneous DCS systems are no more effective than are those placed by laminectomy, and, because of technical problems with epidural systems (mainly lead breakage and migration), the latter may actually be less effective; and (d) at present DCS seems to play a minor role in the treatment of chronic intractable pain.