Backgrounds and Objectives:Lumbar-to-thoracic advancement of epidural catheter is a safe alternative to direct thoracic placement in children. In this prospective randomized study, success rate of advancement of two different types and gauges of catheter from lumbar-to-thoracic space were studied.Materials and Methods:Forty ASA I and II children (up to 6 years) undergoing thoracic or upper-abdominal surgery were allocated to either Group I (18G catheter) or Group II (23G catheter). After induction of general anesthesia a pre-determined length of catheter was inserted. Successful catheter placement was defined as the catheter tip within two segment of surgical incision in radio-contrast study. Intra-operative analgesia was provided by epidural bupivacaine and intravenous morphine. Post-operative analgesia was provided with epidural infusion of 0.1% bupivacaine+1mcg/ml fentanyl.Observations and Results:Catheter advancement was successful in 3 cases in Group I and 2 cases in Group II. Five different types of catheter positions were found on X-ray. Negative correlation was found between age and catheter advancement [significance (2-tailed) =0.03]. However, satisfactory post-operative analgesia was obtained in 35 cases. Positive correlation was found between infusion rate, the number of segment of gap between desired level and the level reached [significance (2-tailed) =0.00]. 23G catheter use was associated with more technical complications.Conclusion:Advancement of epidural catheter from lumbar to thoracic level was successful in only 10-15% cases but satisfactory analgesia could be provided by increasing the infusion rates.