Introduction: Osteoarthritis (OA) is estimated to be the fourth leading cause of disability in the general population. It probably is the most common disease of joints in adults throughout the world. Knee OA accounts for more than 80% of the disease’s total burden and as per an estimate in US population, it affects at least 19% of adults aged 45 years and older. This was a randomised study aimed to evaluate the efficacy of platelet rich plasma (PRP) as a treatment modality for osteoarthritis knee in comparison to arthroscopic management. Materials and methods: This study was conducted from 2018 to 2020 at a tertiary care teaching hospital, under reference number ELMC&H/RCELL2019/39. A total of 70 patients of osteoarthritis knee with grade 2-3 according to the Kellgren-Lawrence classification were selected using computer generated random number among them 35 patients were subjected to arthroscopy (Group II) and 35 were administered platelet rich plasma injection (Group I) and evaluated at 3, 6 and 9 months of follow-up. Both the groups were assessed and scored with the Western Ontario and McMaster Universities Arthritis Index (WOMAC) and Visual Analog Pain Scale (VAS) to compare pre-treatment and post-treatment values. As all the patients in the sample was followed-up, resulting into no loss of subjects. Result: Overall, percentage reduction in VAS score at 3 months, 6 months, and 9 months was 24.45±9.09, 18.45±11.60 and 8.29±14.19%, respectively in Group I and 18.96±5.85, 7.33±8.60 and 3.20±7.39%, respectively in Group II. A statistically significant difference between two groups was observed at 3- and 6-months’ time intervals only (p<0.05). Overall, percentage reduction in WOMAC score at 3 months, 6 months and 9 months was 24.03±11.41, 17.45±9.24, and 9.49±9.80%, respectively in Group I and 11.27±5.73, 5.70±4.78, and -0.13±5.06%, respectively in Group II. At all the three-time intervals, the difference between two groups was significant statistically (p<0.001). Conclusion: This study suggested that both PRP as well as arthroscopy provide a reduction in WOMAC and VAS scores for pain among cases of knee osteoarthritis. Most effective reduction is observed at three months follow-up which thereafter tends to diminish. Of the two modalities, PRP seemed to have an edge over arthroscopic debridement, however, this efficacy was more pronounced for KellgrenLawrence Grade 2 as compared to Grade 3.