PURPOSE: Both erector spinae plane block and wound infiltration are used to improve analgesia following spinal fusion surgery. Herein, we compared the analgesic effect of bilateral erector spinae plane block with wound infiltration in this patient population. METHODS: In this randomized trial, 60 patients scheduled for elective open posterior lumbar interbody fusion surgery were randomized to receive either ultrasound-guided bilateral erector spinae plane block before incision (n = 30) or wound infiltration at the end of surgery (n = 30). Both groups received standardized general anesthesia and postoperative analgesia, including patient-controlled analgesia with sufentanil and no background infusion. Opioid consumption and pain intensity were assessed at 2, 6, 12, 24, and 48 h after surgery. The primary outcome was cumulative opioid consumption within 24 h after surgery. RESULTS: All 60 patients were included in the intention-to-treat analysis. The equivalent dose of sufentanil consumption within 24 h was significantly lower in patients given erector spinae plane block (median 11 µg, interquartile range 5-16) than in those given wound infiltration (20 µg, 10 to 43; median difference - 10 µg, 95% CI - 18 to - 3, P = 0.007). The cumulative number of demanded PCA boluses was significantly lower with erector spinae plane block at 6 h (median difference - 2, 95% CI - 3 to 0, P = 0.006), 12 h (- 3, 95% CI - 6 to - 1, P = 0.002), and 24 h (- 5, 95% CI - 8 to - 2, P = 0.005) postoperatively. The proportion given rescue analgesia was also significantly lower in patients given erector spinae plane block group within 48 h (relative risk 0.27, 95% CI 0.07 to 0.96, P = 0.037). There were no statistical differences in pain intensity at any timepoints between groups. No procedure-related adverse events occurred. CONCLUSIONS: Compared with wound infiltration, bilateral ultrasound-guided erector spinae plane block decreases short-term opioid consumption while providing similar analgesia in patients following lumbar spinal fusion surgery. Chinese Clinical Trial Registry: ChiCTR2100053008.