Shoulder osteoarthritis affect about 32% of patients over 60 years. Conservative treatment are recommended to restore shoulder function while shoulder arthroplasty remains the standard treatment for severe osteoarthritis. When conservative therapies fail and surgical approach is precluded, viscosupplementation with HA may be the treatment of choice. Currently, there is minimal information available comparing the results of Hylan G-F 20 and corticosteroid injections for the treatment of shoulder osteoarthritis. Therefore, the purpose of this study was to examine the results of these two treatments at specific time points with validated outcome measurements. Retrospective comparative cohort study. The study population included 84 patients, 51 of whom treated with Hylan G-F 20 and 33 with a corticosteroid. Gleno-humeral osteoarthritis was graded according to Samilson-Prieto classification and rotator cuff was assessed with MRI. Both groups received three injections 1 week apart and were evaluated using a Visual Analog Scale (VAS) for pain and satisfaction, the Shoulder Pain and Disability Index (SPADI) and the Constant-Murley scale. Outcomes were registered at 1, 3, and 6 months. The Hylan G-F 20 group showed a significant pain reduction (P < 0.05), improvement in the Constant-Murley, SPADI scores (P < 0.05), and satisfaction (P < 0.01) at all three follow-up times. Pain, clinical scores, and subjective satisfaction in the corticosteroid group improved in the first post treatment month only (P < 0.05) compared with the baseline. Overall, lower clinical advantages were found in patients with greater degree of osteoarthritis and rotator cuff tears. Intra-articular injections with Hylan G-F 20 are effective in reducing pain for up to 6 months in gleno-humeral osteoarthritis whereas corticosteroids injections resulte in improvement at 1 month only. In patients with severe osteoarthritis and/or full-thickness, RC tears results tended to be worse.