The uveitogenic T cells that mediate experimental autoimmune uveitis are commonly assumed to be exclusively CD4+. In the present study, we showed that, although a panel of long-term cultured rat uveitogenic T cell lines specific for the interphotoreceptor retinal-binding protein peptide, R16, all expressed CD4,∼ 40% of the R16-specific uveitogenic T cells freshly prepared from Ag-immunized rats were CD8+ αβTCR+, as demonstrated by CFSE staining. We showed that the expansion of these CD8+ αβTCR+ T cells was Ag-specific and that highly purified CD8+ R16-specific T cells were able to induce uveitis on transfusion into naive rats. Moreover, CD8+ uveitogenic T cells more readily switched phenotype from, and to, TCR− CD8− CD4− during in vivo or in vitro activation compared with their CD4+ counterparts. In a previous study, we showed that highly purified CD8+ myelin oligodendrocyte glycoprotein-specific T cells induced more severe autoimmune encephalomyelitis than the corresponding CD4+ T cells. In this study, we show that an interphotoreceptor retinal-binding protein peptide consistently activated a high proportion of CD8+ αβTCR+ T cells, which were uveitogenic in Lewis rats.