Background: modalities for cartilage tissue regeneration. The aim of this study is to study the effect intra-articular platelet rich plasma injections in knee Osteoarthritis (OA). Autologous Platelet-Rich Plasma (PRP) has been advocated as one the recent treatment Methods: Twenty-five patients with mild to moderate osteoarthritis of knee were given single injection of freshly prepared autologous PRP in the affected knee. The Results were evaluated on the basis of the Western Ontario and McMaster Universities Arthritis Index (WOMAC) questionnaire and Visual Analog Scale (VAS) before treatment and 3 weeks, 8 weeks, 16 weeks and 24 weeks after treatment. Results: Statistically significant improvement in all WOMAC parameters and VAS scores were noted in the patients. The beneficial effects lasted for 24 weeks of follow-up with slight deterioration at 24thweek. Conclusion: Intra-articular injection of Autologous Platelet rich plasma provides Pain relief and improves function in patients with mild to moderate knee osteoarthritis.