This is a prospective randomized clinical trial to compare use of a combination of periarticular drug injection with patientcontrolled analgesia (PCA) to PCA alone in post-total knee arthroplasty (TKA). Thirty patients who were admitted for unilateral total knee arthroplasty were selected randomly into an Injection group or a Standard group. The periarticular injection contained Ropivacaine, Ketorolac and Adrenaline, given intra-operatively. The mean amount of opioid used was 22.87 mmol/L in the Injection group as compared to 39.78 mmol/L in the Standard group (p = 0.026). The Injection group had lower pain score at rest and during exercise (p=0.021, p=0.041, respectively), as well as better return to function (p=0.026) and shorter hospital stay (6.1 days, Injection; 7.5 days, Standard, p=0.027). Overall, the group receiving periarticular drugs injection had less pain, less narcotic usage, earlier return to function, similar experience of adverse effects and shorter hospital stays.