Background: Tennis elbow, or lateral epicondylitis, is a common overuse injury that causes pain and functional limitations in the arm. Various treatment options exist, but platelet-rich plasma (PRP) and triamcinolone acetonide injections are frequently used for symptom management. This study aims to compare the efficacy of PRP and triamcinolone acetonide in reducing pain and improving function in patients with tennis elbow. Methods: A retrospective study was conducted at Zoram Medical College, Mizoram, with a sample size of 130 patients diagnosed with tennis elbow. Patients were divided into two groups based on the treatment received: PRP (n=65) and triamcinolone acetonide (n=65). Pain and functional outcomes were assessed using the Visual Analog Scale (VAS) and Disabilities of the Arm, Shoulder, and Hand (DASH) scores, measured at baseline, 1 month, 3 months, and 6 months post-treatment. Statistical analysis was performed to compare outcomes between the groups. Results: Both groups showed significant pain reduction and functional improvement at 1-month follow-up. However, the PRP group demonstrated significantly greater and sustained improvements at 3 and 6 months (p < 0.05) compared to the triamcinolone acetonide group, which showed a decline in symptom relief over time. PRP was particularly effective in providing longer-lasting pain reduction and functional benefits. Conclusion: PRP injections offer superior long-term efficacy over triamcinolone acetonide injections for managing tennis elbow, with sustained pain relief and improved functionality observed at 6-month follow-up. These findings support the use of PRP as a preferred treatment for long-term management of tennis elbow symptoms.