PURPOSE: This research sought to study Platelet-Rich Plasma therapy (PRP) and prolotherapy for shoulder pain and dysfunction related to symptomatic biceps tendinopathy, and to judge effective results. MATERIALS AND METHODS: We selected 100 cases that had significant inflammatory effusion of the biceps tendon (that was shown on MRI), and was refractory to conservative treatment. The cases were followed up for more than one year and were divided into 2 groups. The 1st group received PRP therapy; the 2nd group received prolotherapy under sonographic guidance. We evaluated results for visual analog score (VAS), (Korean Shoulder Society Score (KSS), UCLA Score, Constant Shoulder Score (CSS) for 12 months. RESULTS: There was no significant difference between the 2 groups in the first month after the procedure. However, in the third, sixth, and twelfth months after the procedure, the 1st group showed significant improved results for VAS, KSS, UCLA, and CSS scores compared to the 2nd group (p<0.05). CONCLUSION: Among nonsurgical treatments, both PRP and prolotherapy could be effective against biceps tendinopathy. But, PRP treatment is considered as more reliable method than prolotherapy for maintaining effective results.