The effect of an oral gold preparation, auranofin, on the autoimmune disease mouse MRL/l was examined. Oral administration of auranofin on consecutive days from 6 weeks of age reduced anti-DNA antibody production, IgM rheumatoid factor production, hypergammaglobulinemia, polyclonal B cell activation and renal disease, but did not prevent massive lymphadenopathy or restore the low level of either IL-2 production or mitogen response associated with 1pr gene. In contrast to the effect on autoantibody production, little suppressive activity on the immune response to exogenous antigen SRBC was observed. These results indicate that autoimmune disease in MRL/l mice can be prevented without abrogation of T cell abnormalities and that autoimmune-selective suppression can be induced by chemical compound(s) like auranofin.