US guided procedures for diagnosis or treatment of different forms of arthritis are becoming more and more important. This review describes general considerations for fluid aspiration, articular or periarticular injections and biopsies by US guidance according to the recent literature. Guidelines regarding instrumentation, different techniques, pre- and postprocedural care as well as complications are outlined and in the second part a more detailed overview of different interventions in joints, tendons and other periarticular regions (nerves, bursae, etc.) is included. Furthermore, some newer, more sophisticated techniques are briefly discussed.