40 patients with knee osteoarthritis and scheduled to undergo primary TKA were randomized to receive intraoperative local infiltration analgesia (LIA) with or without the addition of dexamethasone. This study aimed to evaluate the efficacy of the addition of a steroid to LIA. The results indicated that local infiltration analgesia with steroid addition was associated with significantly lower pain on postoperative days 1 and 3, serum C-reactive protein (CRP) levels on postoperative day 3, serum interleukin 6 (IL-6) level in drainage fluid at 24 hours postoperative, and earlier functional recovery compared to the control group.