Sera of patients diagnosed as having the active Vogt-Koyanagi-Harada (VKH) syndrome, Behcet's syndrome or sympathetic ophthalmia as well as normal controls were evaluated by ELISA and by staining of normal human retinal tissue using the avidin-biotin-peroxidase complex (ABC) technique for anti-retinal antibodies. No anti-retinal S-antigen antibodies were detected by ELISA. However, autoimmune antibodies were found against the outer segments of photoreceptors and Müller cells in patients with the VKH syndrome, with lower titers in some patients with Behcet's syndrome, and in a few patients with sympathetic ophthalmia. These results suggested anti-retinal antibodies were present and that retinal autoimmunity may play a role in pathogenesis in varieties of posterior uveitis. In addition, the indirect immunoperoxidase staining technique may facilitate the diagnosis of VKH in uncertain cases.