Sixty six patients aged ≥65 years undergoing total hip arthroplasty (THA) were randomized to receive a pericapsular nerve group (PENG) block with 20 mL 0.2% ropivacaine (n=33) or the same PENG block plus 4 mg perineural dexamethasone (n=33). The primary outcome was time to first rescue opioid. Secondary outcomes included 48-h opioid consumption (morphine milliequivalents), NRS pain at 4/6/12/24 h, quadriceps strength, nerve injury, and blood glucose at 12/24/48 h. Outcomes were assessed through 48 h. Overall, the results revealed dexamethasone prolonged analgesia by ~7.5 h and reduced opioid use and pain scores without affecting strength, neurologic findings, or glucose. These findings suggest perineural dexamethasone is an effective, motor-sparing adjunct to extend PENG block analgesia in elderly THA.