Although the uveitis associated with juvenile rheumatoid arthritis (JRA) is presumed to have an autoimmune etiology, its pathogenesis is unknown. We utilized immunohistochemical techniques to detect the presence of serum antibodies directed against ocular tissues in these patients. The staining patterns of serum from patients with JRA, with and without uveitis, were compared with normal controls. Antibodies directed against epitopes in iris and ciliary body basement membranes, lens epithelium and fibers, Bruch's membrane, and iris and retinal blood vessels were observed in the sera of several individuals. These staining patterns were statistically more frequent among the pauciarticular and polyarticular JRA patients, with and without uveitis, than either the systemic JRA or normal populations. These results demonstrate the presence of antiocular antibodies in the sera of JRA patients, with and without uveitis. Whether those nonuveitic JRA patients with antiocular antibodies will develop uveitis is unknown at this time.