Sjögren's syndrome (SS) is thought to be uncommon in children. An epidemiological study to describe the clinical features distinguishing SS in Japanese children was performed by sending questionnaires to hospitals. A total of 61 cases of SS were reported from 1290 hospitals. The diagnosis of SS was based on histopathological changes and/or sialographic changes in the salivary glands. Forty-two cases had primary SS and 19 were secondary SS with other autoimmune disorders. Fourteen cases (65%) of secondary SS were associated with systemic lupus erythematosus. In primary SS, the initial symptoms were systemic manifestations (fever, exanthema, arthralgia, etc) except for sicca symptoms. In laboratory studies, antinuclear antibodies, elevated serum IgG, rheumatoid factor, anti-Ro/SS-B antibodies were frequently observed.