Musculoskeletal ultrasound (MSUS) is an important modality in evaluating shoulder disease. Following a baseline shoulder conventional radiographic examination, MSUS can be used to screen the painful shoulder. It is accurate in diagnosing full- and partial-thickness tears of the rotator cuff. Both types of tears can be further characterized by size, location, and extension. Postoperatively, the rotator cuff can also be evaluated for recurrent full-thickness tears. MSUS is the only modality that can visualize and characterize synovial disease, without radiographic contrast, and when necessary, US-guided aspiration and biopsy can be performed. Real-time scanning shows the actual motion of the shoulder and its parts. Multiple attempts can be made to achieve optimal images for accurate documentation. Accessibility to MSUS facilitates the rapid turnaround of patients. US imagers and bone radiologists would do well to use MSUS to help their referring physicians establish a quick and accurate diagnosis of shoulder disorders. This article presents a comprehensive, pictorial review of the technical aspects of shoulder sonography as well as major types of pathology that can be diagnosed with US.