One of the most frequent motives of shoulder pain is rotator cuff disease. It is the third most efficacious musculoskeletal malady after low back and neck pain. Shoulder pain is usually due to one of several reasons: subacromial impingement and bursopathy, tendinopathy, a tendon tear, a frozen shoulder, ligamentous instability, and osteoarthritis. Shoulder ultrasonography is approved as the examination of choice for rotator cuff abnormality in many centers around the world since it is an inexpensive and safe tool for investigation of rotator cuff abnormalities. The goal of this study was to determine the ultrasound findings in patients with acute shoulder joint pain, and to compare the ultrasound diagnostic performance to that of MRI.