Background <p>During laparoscopic gynecological surgeries, trocar incisions, pneumoperitoneum and distention of the anterior abdominal wall can cause postoperative pain. Inadequate pain management can increase the risk of postoperative complications. The present study compared the effects of oblique subcostal transversus abdominis plane (OSTAP) block and transmuscular quadratus lumborum (TQL) block on postoperative analgesia and quality of recovery (QoR) in patients undergoing laparoscopic gynecological surgery.</p> Methods <p>A total of 73 patients were enrolled in this prospective, randomized, controlled, double-blind study. The patients were randomly allocated to the OSTAP group (<i>n</i> = 36) or the TQL group (<i>n</i> = 37). General anesthesia was induced following bilateral block administration with 20&#xa0;ml of 0.25% bupivacaine. The primary outcome was postoperative tramadol requirement. Secondary outcomes included postoperative paracetamol requirement, time to first paracetamol and tramadol requirement, total paracetamol and tramadol consumption, visual analog scale (VAS) scores at rest and during movement, and Quality of Recovery-15 (QoR-15) scores preoperatively and 24&#xa0;h postoperatively.</p> Results <p>Postoperative tramadol requirement was significantly lower in the TQL group (<i>p</i> = 0.006). Total paracetamol consumption was also significantly lower in the TQL group (<i>p</i> = 0.002). No significant between-group difference was observed in VAS scores at rest, whereas VAS scores during movement were significantly lower in the TQL group (<i>p</i> = 0.009). The groups were similar regarding QoR-15 scores preoperatively and 24&#xa0;h postoperatively.</p> Conclusions <p>The TQL block reduces postoperative tramadol requirements compared to the OSTAP block. However, both blocks have similar effects on QoR.</p> Trial registration <p>ClinicalTrials.gov, NCT06017401. Registered on August 20, 2023. Retrospectively registered.</p>