Background: Transcutaneous Electrical Nerve Stimulation (TENS) has been widely used for pain relief after surgery instead of opioid analgesics therapy. This study was designed to study the effectiveness of TENS on perianal pain after anal surgery. Methods: Forty-eight patients who underwent anal surgery were evaluated in this suudy. Caudal anesthesia with 1.5% lidocaine 30 ml mixture 1：200,000 epinephrine was performed. TENS was done at 100 Hz for 25 min. duration, postoperatively at 4 hrs and 24 hrs. Pain was also measured at the 4 hrs and 24 hrs postoperatively by visual analogue scale (VAS). VAS value were compared before and after TENS application. Results: Values of VAS after TENS were significantly lower compared to those before TENS. Conclusions: From these results, we concluded, TENS may be effective for postoperative perianal pain relief after anal surgery.