The use of animals has been indispensable to the investigation of the etiology, pathophysiology, and treatment of juvenile arthritis. Because of ethical concerns about studying children, the difficulty of obtaining tissue, and the heterogeneous manifestations and protean course of chronic arthritis in childhood, the scope of potential research has been severely limited. This brief review summarizes a few of the animal models most commonly used in chronic inflammatory arthritis research: subcutaneous air pouch, antigen-induced (including arthritogenic infectious agent), and spontaneous models. In the spontaneous and antigen-induced animal models of arthritis, local and systemic immunoregulatory abnormalities clearly play a major role in the pathogenesis of arthritis. By elucidating the immune response to those antigens, as well as the role of genetics and environment, the pathogenesis of juvenile rheumatoid arthritis may be better understood. At the present time, however, the complexity of these models precludes more definitive interpretation and extrapolation to human diseases.