We studied characteristics of ocular inflammation associated with yersinia infection in six children, three boys and three girls, ranging in age between 4 and 14 years. Four patients developed acute anterior uveitis with aqueous flare and cells, small keratic precipitates, cells in the vitreous, and occasionally with fibrinous exudates, posterior synechiae and macular edema. The uveitis was unilateral in two patients and bilateral in two. In three 10- to 14-year-old patients the uveitis resolved during corticosteroid treatment in 3 to 8 (mean 6) weeks. In a 4-year-old girl with positive antinuclear antibody titers bilateral uveitis lasted for 17 weeks. Two uveitis patients had recurrent episodes. Two patients had mucopurulent bilateral mild conjunctivitis which resolved in 3 to 5 days. All patients had symptoms of reactive arthritis and one had sacroiliitis. All tested patients were HLA-B27 positive. Our results indicate that in HLA-B27 positive children, especially after the age of 10 years, yersinia infection may occasionally trigger reactive iritis or conjunctivitis which often occur together with other HLA-B27 associated rheumatic diseases.