Background: Perioperative pain management strategies in the elderly undergoing hip arthroplasty need special and safe preemptive care. Objectives: The primary aim of this study was to compare the analgesic effects of preemptive ultrasound-guided pericapsular nerve group (PENG) block and lumbar erector spinae plane block (L-ESPB) in the elderly undergoing hip arthroplasty. The time to the first postoperativerescueanalgesiawasmeasured. The secondary aimwas toassesstheeaseof spinalpositioning(EOSP), onsetof sensory block, block performance time, and patient satisfaction. Methods: Before positioning for spinal anesthesia, 69 elderly patients undergoing hip arthroplasty were randomized into three groups (n = 23 per group). The first intervention group received ultrasound-guided PENG block with 20 mL bupivacaine 0.25%; the second intervention group received ultrasound-guided L-ESPB using the same dose of bupivacaine. In the control group, patients received spinal anesthesia without any block. Results: The time to first postoperative rescue analgesic (morphine) was significantly prolonged in the PENG group (13.3 ± 3.5 h) compared to the L-ESPB (9.5 ± 2.3 h) and control (2.6 ± 0.4 h) groups. The EOSP score was significantly higher in the PENG group compared to the L-ESPB and control groups (P < 0.001). The block performance time and oneset of the sensory block were significantly shorter in the PENG group compared to the L-ESPB group. The highest patient satisfaction scores were observed in the PENG group. Conclusions: Preemptive pericapsular nerve group block postponed the need for postoperative analgesia and eased spinal positioning compared to L-ESPB in the elderly undergoing hip arthroplasty.