Nutritional status, with emphasis on nutrients involved in inflammatory processes, was investigated in 26 girls with juvenile chronic arthritis (JCA) and in healthy controls. Children with JCA had decreased plasma selenium compared to controls. Glutathione peroxidase activity in plasma was similar in both groups but the activity in blood was slightly depressed in JCA. The decrease in blood glutathione peroxidase was more pronounced in patients with high to medium disease activity. Ascorbic acid was measured in plasma, platelets, mononuclear cells and granulocytes. A slight decrease in granulocyte ascorbic acid was observed in patients but in plasma, platelets and mononuclear cells no difference was observed. Serum alpha-tocopherol, blood folate and serum cobalamine was the same in both groups. Several patients, especially in the youngest group, exhibited impaired growth. Serum creatinine and arm muscle circumference were lower in the arthritic patients indicating a lower muscle mass. These changes were more pronounced in patients with systemic or polyarticular onset of the disease. The possibility that the changes in nutritional status in patients with JCA can be corrected by dietary supplementation needs further investigation.