In an experimental model of interphotoreceptor retinoid binding protein (IRBP)-induced experimental autoimmune uveitis (EAU) in Lewis rats, EAU onset was suppressed by pretreatment with anti-idiotypic antibody (TRD3). In the pretreated group, the titers of anti-IRBP antibody and idiotypic antibody were lower and the titer of anti-idiotypic antibody was higher than in the control group, and the skin test (DTH) against IRBP was also suppressed. Histopathological findings of the control group showed destruction of retinal outer granular layer, loss of the outer segment and lymphocytic infiltration, although no definite inflammatory signs appeared in the pretreated group. We suppose that the mechanism of idiotypic suppression is via induction of idiotype-specific or idiotype-related suppressor T cells.