Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease that is mainly directed to the joints, affecting the synovial membrane, the cartilage and also the bone. This disease affects 1% to 2% of the world population and is associated with significant morbidity and increased mortality. RA experimental models have allowed a great deal of information to be translated to the corresponding human disease. This review summarizes some of the most relevant findings targeting immunomodulation in arthritis. Some general guidelines to choose an adequate experimental model and also our experience with arthritis are supplied.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Univ Estadual Paulista UNESP, Biosci Inst, Dept Microbiol & Immunol, BR-18618000 Sao Paulo, BrazilChaim Sheba Med Ctr, Zabludowicz Ctr Autoimmune Dis, IL-52621 Tel Hashomer, IsraelUniv Estadual Paulista UNESP, Biosci Inst, Dept Microbiol & Immunol, BR-18618000 Sao Paulo, BrazilFAPESP: 11/17325-4