Since increased levels of sCD23 were demonstrated in patients with autoimmune diseases, plasma and synovial fluid sCD23 levels were examined in 22 patients with juvenile chronic arthritis (JCA) and in 10 children undergoing arthrocentesis for orthopedic disorders. There was no significant difference in plasma sCD23 concentrations between patients with pauciarticular and polyarticular onset. Plasma and synovial fluid sCD23 concentrations were found to be significantly increased in JCA patients as compared to controls. However, plasma sCD23 levels were not positively correlated with laboratory parameters showing disease activity such as erythrocyte sedimentation rate, C-reactive protein, serum IgG and IgA. It was concluded that increased production of sCD23 in peripheral blood and synovial fluid might be important in the pathogenesis of JCA. However, determination of this immunological parameter provides no useful clinical information about disease activity and management.