With technical improvements (higher frequency and extended field-of-view sonography) the ability of ultrasound to detect pathology in the musculoskeletal system has been greatly increased. As in MRI, and unlike conventional radiography, soft tissue lesions in muscles, tendons and occasionally in joints can be shown directly. An advantage is real-time imaging of joints during stress. A disadvantage is limited demonstration of internal structures within joints. This paper provides an overview of various pathologies with emphasis on acute disorders.