After patient history and clinical evaluation, sonography is a first-line modality in the orthopedic diagnostic algorithm together with laboratory results and standard radiographic findings. As an inexpensive investigation without known adverse effects it is used (and also repeated in the course of the disease) for the dynamic control of joint movements, and especially for imaging soft tissues. Sufficient training in the use of ultrasound in the musculoskeletal system is required; individual investigations are relatively time-consuming. The procedure is especially useful in evaluating the shoulder, hand, and knee regions and rheumatic illnesses.