Sera from 12 patients with juvenile rheumatoid arthritis (JRA) with active iridocyclitis were incubated with frozen, sectioned, whole human eye tissue. Antibodies were detected using fluorescein conjugated goat F(ab')2 antibody to human IgG by immunofluorescent microscopy. Immunofluorescence was determined on tissue from the iris, retina, and 3 portions of the ciliary body. Sera of patients with JRA with iridocyclitis were compared to sera from patients with JRA with and without antinuclear antibodies (ANA) and healthy children. An increased frequency of antibody to the human iris was seen with sera of patients with JRA with iridocyclitis compared to healthy children's sera. A higher frequency of antibody was also noted to human retina in sera of patients with JRA with iridocyclitis compared to patients without ANA and healthy children. No increased frequency of antibody was detected to ciliary body. Sera of 7 patients with JRA with iridocyclitis were also compared during a time of inactive eye disease to a time of active disease. No difference in binding to eye tissue was detected at times of inactive disease compared to controls. Our results demonstrate the presence of antibody to iris and retina by immunofluorescence in the sera of patients with JRA with iridocyclitis.