Epstein-Barr virus-related antibody titers were determined in 30 patients with anterior uveitis, 45 with pan-uveitis, including 19 with Behçet's disease, 11 with Vogt-Koyanagi-Harada's disease and 15 with unclassified pan-uveitis, and 144 age-matched healthy controls. The frequencies of anti-VCA (viro-capsid antigen) and anti-EA (early antigen) in uveitis patients and in controls were similar, but the frequency of sera with elevated titers (greater than or equal to 1:160) and the geometric mean titer of anti-VCA in the patients with anterior uveitis was significantly higher than in the controls (P less than 0.025, P less than 0.01) and in the patients with pan-uveitis (P less than 0.001). The frequency of sera with elevated titers of anti-EBNA (Epstein-Barr virus associated nuclear antigen) (greater than or equal to 1:160) in the patients with pan-uveitis was significantly lower than in the controls (P less than 0.02) and in the patients with anterior uveitis (P less than 0.01). Among the patients with pan-uveitis, there was no significant difference in the pattern of antibodies. These data are compatible with the interpretation that there may be both anatomical and immunological differences between anterior and pan-uveitis.