The treatment of pain in the back and extremities remains empirical. The application of surface electrodes to the dorsal columns of the spinal cord has been used by Shealy. The rationale. for dorsal column stimulation has been the “gate control theory” of pain proposed by Melzack and Wall. Transcutaneous electrical nerve stimulation is well recognized for its effectiveness in pain relief. The authors studied 48 cases of group A (physiotherapy, medication) and compared them with 43 cases of group B(physiotherapy, medication 'and diadynamic current), in the Department of Orthopedic Surgery, Yonsei University Hospital, from April, 1983, to June, 1984. The results were as follows: 1. Significant relief of pain was noted in group B in long term follow up of acute pain in the back and extremities. 2. In long term follow-up of group B, there was more improvement than in group A, especially when there was radiating pain in the extermities with or without back pain. 3. In long term follow-up according to the causes of the pain, there was more improvement in group B than in group A in cases of herniated nucleus pulposus and low back syndrome. From a consideration of these studies, it was concluded that satisfactory results were obtained from diadynamic current treatment for the patient with pain in the back and extremities.