Experimental autoimmune uveoretinitis (EAU) was induced in Lewis rats and the inflamed retinas were examined for IFN-gamma, IL-2, IL-4, and IL-10 mRNA production at serial time points using the reverse transcriptase-polymerase chain reaction. IFN-gamma, IL-2, IL-4, and IL-10 mRNAs were all detected 24 hr before the earliest time point at which histological changes have previously been detected. IFN-gamma, IL-2, and IL-4 mRNA expression peaked during the active phase of the disease and declined in parallel with lymphocyte numbers as the inflammation resolved. IL-10 mRNA levels increased more slowly, reaching a maximum at later stages of disease. The observed pattern of cytokine mRNA expression in the retina in EAU is similar to that reported in experimental autoimmune encephalomyelitis (EAE). The increase in IL-10 mRNA expression in late disease may reflect a role in disease resolution as previously proposed in EAE.