Musculoskeletal ultrasound is increasingly utilized in the assessment of rheumatic diseases. Pathological changes can be identified through grayscale features, whereas increased Doppler activity indicates heightened vascularity in tissue inflammation. Ultrasound is valuable for evaluating pain or dysfunction arising from soft tissue or bone injuries, tendon or ligament issues, arthritis, synovitis, crystal deposition diseases, joint effusion, and intra-articular bodies. Additionally, it can detect neurovascular entrapment, nerve masses, joint subluxations, soft tissue swelling, fluid collection, and foreign bodies within the soft tissue. Ultrasound-guided invasive procedures, such as tissue biopsies and joint or soft tissue injections, contribute to accurate diagnosis and clinical effectiveness. This chapter discusses the general and joint specific indications of ultrasound in musculoskeletal disorders.