Background and objectives <p>The increasing importance of ultrasound in paediatric rheumatology is reflected in many scientific projects, in the increasing number of training courses and in its everyday use. Several international working groups have been working in the last few years to develop standardised examination protocols for joint sonography.</p> Materials and methods <p>The article summarises the current progress in ultrasound diagnostics in children and adolescents with rheumatic diseases, and discusses technical developments, improved training opportunities, the implementation in the treat-to-target management and the extension to other fields of application in paediatric rheumatology.</p> Results <p>To determine disease activity and to describe pathological findings, sonographic definitions were agreed upon, taking into account age-dependent changes in the musculoskeletal system, and first paediatric scoring systems were tested in validation studies. Several publications in the last few years have shown that joint sonography is superior to clinical examination in certain joint regions. Several studies have also demonstrated its important role in therapy and follow-up monitoring. Even outside of the joint regions, such as in the depiction of salivary glands or muscles, ultrasound is gaining increasing importance in paediatric and adolescent rheumatology.</p> Conclusion <p>Advances in technical development and expertise in the field of ultrasound have led to ultrasound becoming an important tool in the care of children and adolescents with rheumatic diseases.</p>