Eighty-four patients undergoing a posterior lumbar interbody fusion procedure were randomized to receive an ultrasound-guided, bilateral erector spinae plane block (ESPB; n=42) or no block (control; n=42) after anesthesia induction. The primary outcome of interest was the quality of recovery at 24 hours post-operation. Secondary outcomes of interest included the Numeric Rating Scale (NRS) pain scores at rest and during mobilization, time to first rescue analgesia, remifentanil and morphine consumption, the incidence of adverse events, and patient satisfaction. Results revealed significantly improved quality of recovery at 24 and 48 hours post-operation in the ESPB group vs. control. Moreover, NRS pain scores at rest and during mobilization in the first 8 hours, remifentanil and morphine consumption, time to first rescue analgesia, and patient satisfaction were all in favour of the ESPB group. No differences in the rate of adverse events were observed.