The effects of epidural fentanyl in combination with 0.5% bupivacaine were observed in randomized 60 patients undergoing lower abdominal surgery. The time of onset, segmental spread and duration of analgesia, changes in arterial blood pressure and heart rate and the incidence of side effects were observed after epidural injection of the drugs. The patients were divided into three groups; Group I: 0.9% NaCl 2 ml combined with 20ml of 0.5% bupivacaine, Group II: 0.9% NaCl 1ml and fentanyl 50ug (1 ml) combined with 20 ml of 0.5% bupivacaine, Group III: fentanyl 100 ug (2ml) combined with 20 ml of 0.5% bupivacaine. The results were as follows. 1) The time of onset was significantly short in group III (P < 0.01) 2) The level of sensory blockade 30 minutes after epidural injection in group III was 2-3 segments higher than group I. 3) The mean duration of analgesia was significantly long in group III compared to groups I and II (P<0.01). 4) The cardiovascular changes were not significantly different among the patients of the three groups.6) The side effects including mild hypotension, nausea and vomiting, voiding difficulty, itching and backache were not significantly different in the occurrence among the patients of the three groups. From the above results, it is suggested that fentanyl 100ug combined with 0.5% bupivacaine for epidural anesthesia has some benefits in its onset, spread and postoperative analgesia.