We report here five pediatric patients with human T-lymphotropic virus type 1 (HTLV-I) uveitis. The patients were one boy and four girls aged between 3 and 14 years. The transmission route was considered to be breast feeding from their mothers. All patients had unilateral uveitis and the ocular symptoms were similar to those in HTLV-I uveitis in adults. The ocular inflammation responded to therapy with topical or systemic corticosteroids, but recurred in three patients. HTLV-I provirus DNA was detected by polymerase chain reaction (PCR) from infiltrating cells in the anterior chamber in one patient. The percentage of HTLV-I-infected cells in the peripheral blood mononuclear cells was measured by quantitative PCR, and the values were high (2.9 approximately 7.3%) in three cases tested as compared with an asymptomatic carrier. These five cases show that HTLV-I uveitis can be induced in a relatively short period (3 approximately 10 years) after the viral infection, and that HTLV-I uveitis should be considered as one possible etiology of uveitis in children, particularly in a viral endemic area.