106 patients undergoing elective posterolateral total hip arthroplasty (PLTHA) under spinal anesthesia (SA) were included in this non inferiority randomized controlled trial in which patients were randomly allocated to receive a supra-inguinal fascia iliac block (SFIB; n=53) or pericapsular nerve group blocks (PENG; n=53). The primary outcome of interest was pain at rest measured by numeric rating scale (NRS) 6 hours postoperatively. The secondary outcomes of interest included NRS pain at rest and on mobilization for all other timepoints during the first 48 hours [1 hour and 6 hours after surgery; and on postoperative days (POD) 1 and 2 at 8am, 1pm and 6pm), total morphine consumption, timed up-and-go test (TUG), the 2-min walking distance test (2MWT), 6-min walking distance test (6-MWT], the quality-of-recovery 15-items score (QoR-15), incidence of falls and orthostatic intolerance at 48 h after surgery and morphine-related side effects on POD 1 and 2. Other secondary outcomes included the Tampa Scale of Kinesiophobia (TSK), length of hospital stay, Douleur Neuropathique 4 Questions (DN4) scale, and the French-validated International Pain Outcomes (IPO) questionnaire for pain management. The results of the study show that PENG was non inferior to SFIB with respect to post operative pain control at 6 hours. No significant differences were found between groups with respect to pain trajectories during the first 48 hours, functional recovery and performance outcomes (TUG, 2MWT, 6MWT, QoR-15) at all time points, or for TSK, DN4 and IPO. There were also no significant between-group differences observed for cumulative morphine consumption or morphine related side effects, incidence of orthostatic intolerance and length of stay.