Background: To compare the efficacy of Ultrasound-guided PRP at the site of tendinitis VS subacromial injection of PRP in supraspinatus tendinitis, in terms of patient outcome and improvement in range of movements of the shoulder joint. Materials & Methods: Randomized single-blinded controlled trial with 2 months & 4 months follow-up using a visual analogue scale, ROM, SPADI & ASES. A total of 60 patients between the age group of 20–70 years old of both sexes were diagnosed for the first time and not treated by any other modality, fulfilling the inclusion criteria of rotator cuff tendinitis. Results: Descriptive and inferential statistical analysis has been carried out in the present study using a student t-test (two-tailed, dependent & independent) and Chi-square/ Fisher test. The improvement in VAS score, SPADI scores, ASES scores, [ abduction], and in patients who received USG PRP injections was statistically more significant compared to patients who received blind PRP injections as inferred by P-value of <0.001, both at 2 months and 4 months follow up. Conclusion: Our study concludes that the efficacy of USG platelet-rich plasma to relieve the pain of rotator cuff tendinitis is better than blind PRP over a short-term follow-up period.