A number of autoimmune disease models have been used to examine the anti-inflammatory and immunosuppressive effects of tolerogenic dendritic cells (tDCs). The aim of the present study was to investigate whether rosiglitazone-mediated DC (Rosi-DC) therapy suppressed arthritis in a collagen-induced arthritis (CIA) mouse model. The results presented herein show that type II collagen-pulsed Rosi-DCs ameliorate the inflammation associated with CIA via the induction of Treg cell population. These results suggest that rosiglitazone-mediated DCs hold promise as a novel therapeutic strategy for RA.