Background: Opioids and local anesthetics have been administered epidurally for the purpose of the postoperative analgesia. However opioids have a serious risk of respiratory depression and local anesthetics have the risks of hypotension, sensory block, or motor one. In recent years, reports of spinal administration of midazolam for acute postoperative pain control have appeared in the literature. This study was performed to observe the effect of epidural midazolam in patient-controlled analgesia (PCA) device. Methods: Forty-five patients scheduled for the elective total hysterectomy were randomly selected; epidurally take morphine only (group I, n=15), morphine plus 0.1% bupivacaine (group II, n=15), or morphine plus midazolam (group III, n=15). The visual analogue scale (VAS) at rest and with movement, the sedation score, the degree of the satisfaction, the total amounts of a morphine usage, and the incidence of the side effects were observed. Rusults: The VAS at rest of group II and III were decreased significantly than that of group I. The VAS with movement of group III was significantly decreased than that of group I and II. The sadation score and the cumulative dose of a morphine were statistically insignificant within groups. Conclusion: Epidural morphine plus midazolam was proven to be clinically effective in the post-operative pain control especially for the pain with movement, compared with epidural morphine only and morphine plus 0.1% bupivacaine.