It is important to understand the characteristics of ultrasound (US) images of the musculoskeletal system (bones, joints, musculoskeletal muscles, tendons, ligaments, and nerves). US images of greater tuberosity, lesser tuberosity, bicipital groove of humeral bone, and subscapularis tendon of rotator cuff are obtained by anterior scanning of the shoulder joint. The long head of the biceps tendon is seen in the bicipital groove. In order to visualize the supraspinatus tendon and the infraspinatus tendon of the rotator cuff, patients are asked to place their hand on their back. The intact rotator cuff shows a convex shape with a fibrillar pattern in the longitudinal view. In the case of posterior scanning, short axis images of the glenohumeral joint are obtained. Characteristic findings of a rotator cuff tear are depression or flattening of peribursal fat echo, low echo area of the tendon, and irregularity of the greater tuberosity echo line. Calcific tendinitis exhibits a high echo area with acoustic shadow in the tendon. US diagnosis of musculoskeletal disorders is becoming more and more common, and further advances in this area are expected.