During the past decade the use of epidural opioids for treatment of chronic as well as postoperative pain has increased Epidural droperidol significantly reduced the side effects of epidural morphine without any appreciable toxicity, except possibly sedation. The purpose of this study was to assess the side effects and potentiation of analgesia of epidural morphine by dose-related droperidol. The results were as follows: 1) Duration of analgesia and pain score: There was no significant difference between morphine and dose-related droperidol groups. 2) Pruritus: Droperidol did not affect the incidence of pruritus with epidural morphine (P>0.05). 3) Nausea and vomiting: Significantly fewer patients experienced nausea and vomiting (16.7%) with droperidol 2.5mg(P<0.001). 4) Hypotensive episode Hypotension occurred in the groups with droperidol 1.25 mg (27. 8%) and 2.5mg(33.3%). 5) Sedation: It there was increased severity and incidence of sedation with dose related epidural droperidol. 6) Respiratory depression: There was no patient with respiratory depression in the morphine or droperidol group. 7) Extrapyramidal symptoms and others: There was no extrapyramidal symptom in the group with morphine and 0.25 mg droperidol, but 3 patients in the group with l.25 mg droperidol and 5 patients in the group with 2.5 mg droperidol how extrapyramidal symptoms. One patient in droperidol 2.5 mg developed suspicious NMS. It is suggested that the use of epidural droperidol to reduce the side effects of morphine may not be appropriate.