Introduction:Total knee arthroplasty (TKA) is associated with intense postoperative pain for which effective analgesia is essential to facilitate early postoperative recovery. Adductor canal block (ACB) and local infiltration analgesia (LIA) have become increasingly involved in postoperative pain management after TKA. We aimed to compare their efficacy and outcomes in patients undergoing TKA. Materials and Methods: Sixty patients undergoing unilateral TKA were randomized to receive either postoperative single-injection ACB (Group A) or LIA (Group L) during the operation. All patients received spinal anaesthesia. Primary outcome was total morphine consumption over postoperative 24 hours. Visual analog pain scale, time to first and total dosage of rescue analgesia, performance-based evaluations [timed-up and go (TUG) test, quadriceps strength], side-effects, length of hospital stay and patient satisfaction were measured. Results: Fifty-seven patients were available for analysis. Median total morphine consumption over 24 and 48 postoperative hours of Group A were significantly less than Group L (6/10 mg vs 13/25 mg, p, 0.008 and 0.001, respectively). Similarly, Group A had significantly lower VAS at postoperative 6, 12 and 18 hours, VAS at ambulation on postoperative (POD) 1-3, better TUG tests on POD 2 and during POD 3 than those of Group L. However, quadriceps strength and patient satisfaction were not different between both groups. Conclusion:Patients undergoing TKA with single-injection ACB required less postoperative opioids than those with LIA. Furthermore, multimodal analgesia using ACB provided better postoperative analgesia, as well as performance-based activities, than those with LIA.