Thirty-three patients with systemic onset JRA were followed up for 4 to 24 years (median 10 years). None had positive RF or ANA. Most patients developed polyarthritis. Cardiac involvement occurred in 14 patients (42%). Cardiac prognosis was good for pericarditis but seemed to be worse for myocarditis or perimyocarditis. Three patients contracted renal amyloidosis (9%). Severe growth retardation was observed in 39 per cent. Half of the patients had low activity or were in remission after in average 5.9 years' duration of the disease. Seventy per cent of the patients were in a good functional state. Patients with less than average radiological progression during the first 5 years of disease and those with onset of disease after the age of 5, seemed to have a better functional prognosis.