Background: Osteoarthritis, one of the common musculoskeletal diseases, affects about half of the world population at some point in their lives. It is associated with pain and functional limitations. The use of autologous platelet rich plasma (aPRP) either alone or in combination with hyaluronic acid (HA) for treatment of knee osteoarthritis will continue to get attention due to its anti-inflammatory and growth factors releasing effects, viscous-supplementation effect of hyaluronic acid and the side effects of the commonly used NSAIDs.The aim of this study was to compare the effectiveness of addition of hyaluronic acid to platelet rich plasma in the treatment of chronic osteoarthritis knee-joint..Methods: Following the approval of our institutional Ethical Review Committee, fifty two patients who had non-traumatic chronic osteoarthritis of knee joint pain (>3 months) and kellgren-lawrence score of 2 and 3, were randomized into two groups, A and B. Group A had intra-articular injection of 4 mls autologous PRP, 300 IU of HA and with 2 mls of 0.5% plain bupivacaine and Group B received intra –articular injection of 4 mls autologous PRP plus 2 mls of 0.5% plain bupivacaine administered blindly. Pain intensity and functional disability were assessed, with numerical pain rating (NPR) scale and pain disability questionnaire (PDQ), at 1, 3 and 6 months follow up. Results: Majority of the patients (90.4%) were in the age range of 41-60 years. What is the M: F ratio? At 6 months follow up, significant reductions in pain intensity (NRS) in the two groups were observed 7.15 ±1.0 vs 1.33±0.5 and 7.10 ± 1.2 vs 2.65±1 respectively for groups A and B. The lower pain score observed among group A at 6 months follow up was statistically significant, p<0.05. There was an improvement in functional activity (assessed by activity rating scale) among both groups. Pre intervention, 25.9% and 74.1% of patients in group A had moderate and severe limitations to movement respectively in com