Pigmented guinea-pigs were immunized by a single bilateral footpad injection of their own retina from one enucleated eye, mixed with complete Freund's adjuvant. Ocular inflammation started on the third week, and was still detectable in the fourth month. Daily subcutaneous injections of Cyclosporine (CsA) (20 mg/kg) from the day of immunization totally prevented the ocular disease, clinically and histologically, confirming earlier experiments in S-antigen induced experimental autoimmune uveoretinitis in rats. When CsA injections (20 mg or 10 mg/kg) were started at the onset time of EAU, a rapid regression of the inflammation occurred. This curative therapy was given during two months. No relapse was observed after having stopped the treatment. On the fourth month, only mild lesions of photoreceptors were found histologically, compared to extensive retinal destruction in controls. Most control guinea-pigs developed antibodies to antigens contained in guinea-pig retinal extract as tested by ELISA. The serum antibody content was lower in treated than in control animals. The autologous model of EAU in pigmented guinea-pigs seems to be very appropriate for testing immunosuppressive drugs in conditions close to clinical practice.