Shoulder pain, often caused by subacromial chronic bursitis (SACB), can be effectively addressed using ultrasound (US) in orthopedic, rheumatological, and rehabilitative settings. This study compared US-guided hydrodilation with a classical blind approach using triamcinolone acetonide in treating SACB. Patients’ shoulder functionality was assessed over 90 days. Both treatments significantly reduced pain, but the US-guided hydrodilation group required no re-treatment, suggesting it as the preferred method for treating SACB due to its efficacy and minimal invasiveness.