We report the clinical results observed in a series of 46 patients with chronic pain who underwent spinal cord electrical stimulation. Candidates were selected according to previous clinical criteria and they were followed-up during a period of 5 to 27 months. Fifteen patients had a residual backache after surgery of the lumbar spine, 19 patients complained angina pectoris, 5 patients peripheral vasculopathies, and 7 subjects had different types of neurogenic pain. A total of 5 patients failed to complete the trial period of 7 to 10 days. Among the 34 patients who continued to use the medullar stimulation, good results were obtained in 75% of cases of backache , 100% of patients with angina and vasculopathies, and 50% of patients with neurogenic pain. There were no relevant complications. We conclude that the results of spinal cord stimulation can be improved by using more strict indications, by performing a previous test period before definitive implantation, and by achieving a large technical experience.