Background: The continuous epidural analgesia is a popular method in the management of postoperative pain. However, the exact regimen for the optimal analgesia is still in dispute. In this study, we evaluated the effect of an initial loading dose prior to the continuous epidural infusion after a brief surgery, which may have some residual effects of local anesthetics that is used for the intraoperative epidural anesthesia. Methods: Seventy five patients required epidural anesthesia with 15 ml of 2% mepivacaine for the perianal surgery were randomly divided into three groups: Group 1, being the control group (n=25) did not received postoperative epidural pain control. But, group 2 (n=25) and 3 (n=25) received continuous epidural analgesia with local anesthetics and morphine immediately after surgery. In Group 2, the patients received continuous epidural infusion without initial loading dose. In Group 3, the patients received initial loading dose (1% mepivacaine 6 ml and morphine 1 mg) and followed by continuous epidural infusion. We evaluated the number of patients who needed adjuvant analgesics, the pain score, and incidence of side effects for the postoperative 48 hours. Results: At postoperative 12 hours, in group 3, the two variables, the number of patients who needed analgesics and the pain score showed a statistical significance with low scores compared with group 1 and 2. At postoperative 24 and 48 hours, the two variables indicated above did not show any differences in group 2 and 3. The incidence of side effects is not different among the three groups. Conclusions: The loading dose prior to continuous epidural infusion is necessary after a brief surgery which may have some residual effects of local anesthetics that is used for the intraoperative epidural anesthesia.