Introduction: Tennis elbow is due to defective reparative process at lateral epicondyle. With repetitive use of wrist there is a micro tear at origin of extensor carpi radialis brevis. Conventional treatment methods do not try to alter the poor healing property of the tendon. Platelet rich plasma is a new treatment option aimed at reversing this degenerative process. Aim- This study is designed to find out the effectiveness of platelet rich plasma in the treatment of tennis elbow Materials & Methods- Patients with clinical signs and symptoms of chronic lateral epicondylitis during June 2016 to October 2017 attending the Orthopaedics outpatient department of RMMCH, Chidambaram were evaluated. A prospective study was done with Platelet rich plasma for tennis elbow patients and were followed up for one year. Results- 25 patients with Tennis elbow were treated with platelet rich plasma injection. They were followed up for one year with Pain pressure threshold using manual algometer. The patient showed a steady improvement in PPT up to six months of follow up. After which the effects seems to have started diminishing. Conclusion- PRP is a new effective means to treat chronic lateral epicondylitis. PRP is superior at six months of follow up. After which the beneficial effects seems to have reached a plateau. The patients treated with PRP has shown better pain relief and improved function .Surely PRP will change the way orthopaedicians are treating tendinopathies in the future However, further studies with longer follow up and with repeat injections are suggested to get definite conclusion.