Background: Osteoarthritis (OA) is a chronic, non-inflammatory rheumatologic disease which affects the synovial joints. The present study was conducted to assess the role of PRP in management of osteoarthritis of the knee. Materials & Methods: 65 patients of osteoarthritis of the knee of both genders were enrolled. Cartilage thicknesses were measured radiologically by ultrasound before and at third and sixth months after treatment. The severity of pain was evaluated by using VAS. Results: Out of 65 patients, males were 30 and females were 35. Right side was involved in 34 cases and left in 31 cases. The mean VAS before treatment was 5.4, after 3 months it was 2.3 and after 6 months it was 0.8. The difference was significant (P< 0.05). The mean cartilage thickness before treatment was 0.5 mm, after 3 months was 0.7 mm and after 6 months it was 0.8 mm. The difference was significant (P< 0.05).