Background: The aim of this randomized controlled study was to compare the effects of ultrasound-guided erector spinal block (ESPB) with those of opioid- based analgesia. Methods: This prospective, randomized, open, blinded-endpoint study evaluated the analgesic effects of ESPB in patients undergoing lumbar surgery. The outcome measures were remifentanil and propofol consumption during operation, fentanyl consumption during 24 hours after anesthesia induction. Results: Data from fifteen patients were analyzed with seven and eight patients in the control and ESPB groups, respectively. There was difference between the groups in remifentanil consumption (median μg/kg lean body mass) 44.1 ［37.1, 49.3］ and 22.4 ［17.3, 26.1］; p = 0.002 in control and ESPB groups during operation. There was no difference between the groups regarding other outcomes including fentanyl consumption for postoperative analgesia. Conclusions: ESPB reduced remifentanil consumption during operation, but did not reduce fentanyl consumption for postoperative analgesia within 24 hours after anesthesia induction in lumbar spine surgery.