Postoperative pain following total knee arthroplasty (TKA) can significantly hinder recovery and patient satisfaction. Looking at randomized trials testing, this review determines whether a single IV dose of dexamethasone given before total knee arthroplasty can improve recovery. Across six studies—most published recently and judged low risk of bias—dexamethasone consistently reduced postoperative pain at several time points, including 6–24 hours, 72 hours and even at 6 months. It also lowered opioid use over the first 72 hours and cut the risk of postoperative nausea and vomiting. Importantly, no increase in infection or other safety concerns emerged. While dosing and timing varied between trials, the overall evidence suggests that preoperative dexamethasone is a safe, effective adjunct that enhances early pain control and supports recovery.