ABS TRACT Objective:We compared the analgesic efficacy of ultrasonography (USG)-guided quadratus lumborum (QL) and transversus abdominis plane (TAP) blocks in infants undergoing elective unilateral inguinal hernia surgery (IHS). Material and Methods: This single-center, randomized, single-blind, 2-arm clinical trial included 60 infants undergoing elective IHS (aged 1 month to 1 year) with ASA I-II. The patients were randomized into QL block (Group A) and TAP block (Group B) groups. For both groups, 0.3 mL/kg of 0.25% bupivacaine was injected under USG guidance. Age, sex, weight, anesthesia duration (min), surgery duration (min), and recovery duration (min) were recorded. The heart rate (HR) was recorded at baseline, after anesthesia induction, and at 15 and 30 min after the blocks. Postoperatively, patients were evaluated based on their Face, Legs, Activity, Cry, and Consolability (FLACC) scores at 0, 1, 2, 6, 12, and 24 h. We also recorded the first analgesic duration, analgesic requirement, rescue analgesic requirement, and complications. The primary outcome of the study was FLACC score. Results: Sixty patients completed the study protocol. There were no significant differences between the groups in terms of age, sex, weight, anesthesia duration, surgery duration, recovery duration, or FLACC score or HR in the first 24 h postoperatively. The analgesic requirement, first analgesic requirement time, and rescue analgesic requirement were not significantly different between the groups (p>0.05 for all comparisons). Conclusions: QL and TAP blocks showed similar analgesic efficacy in infants undergoing IHS.