We evaluated caudal lidocaine with morphine as a technique for providing not only operative anesthesia for perianal surgery, but also for pain relief in the postoperative period. Through the sacral canal, lidocaine with 3mg of morphine(group ll), or lidocaine with 5mg of morphine(group lll) was administered in to the epidural space, and efficacy of this method for the relief of postoperative pain was compared with that obtained after caudal anesthesia with lidocaine only(group l). The analgesic results in the morphine groups were superior to those in lidocaine only group, and the duration of the analgesic effect of the morphine groups lasted from 13 to 48 hours. The 3mg dosage of morphine was sufficient to lengthen the anesthetic duration. We failed to find out any relationship between the analgesic duration and the morphine dosages. The complications of this method were minimal, and there was no case of central depression.