Background: Rotator cuff tears are a common musculoskeletal injury, and platelet-rich plasma (PRP) therapy has emerged as a potential treatment. This study evaluates the efficacy of leukocyte-rich PRP in treating interstitial or partial rotator cuff tears. Methods: A prospective study was conducted on 100 patients with diagnosed interstitial or partial rotator cuff tears. Patients were divided into two groups: one receiving leukocyte-rich PRP injections and the other receiving saline injections as a control. Outcome measures included pain scores, functional assessment using the Constant-Murley score, and MRI evaluations at baseline, 3 months, and 6 months post-treatment. Results: Significant improvements in pain and function were observed in the PRP group compared to the control group at both 3 and 6 months. MRI findings also showed better healing responses in the PRP group. Conclusion: Leukocyte-rich PRP is an effective treatment for interstitial or partial rotator cuff tears, providing significant improvements in pain relief, function, and tissue healing.