A case has been reported in which stereotaxic percutaneous cordotomy has been performed for the treatment of an intractable pain in the arm. The 60-year-old male was admitted to this hospital because of right arm pain which was persistant, so severe and intractable to various medical treatment for 2 months prior to admission. The pain in association with right Horners' syndrome has been produced by the involvement of carcinoma in the right apex of the lung to the cords of brachial plexus and superior cervical ganglion. Since the patient was so emaciated and distressed with the pain, the percutaneous cordotomy was indicated for him to cure the pain. Under the local anesthesia the patient was maintained in the supine position with his head held lightly on the head holder. And unilateral high cervical cordotomy by the percutaneous stereotaxic method was performed on the left through C-C2 interlaminar space under radiographic and impedance measurements, which relieved the pain completely with no development of significant postoperative complications. It was simple, safe and effective for the patient who has poor general condition because it does not require a general anesthesia or a period of wound healing and the cooperation of the alert patient eliminates the possibility of paralysis and enhances the changes of securing the desired sensory loss.