The aim of this study was to determine the clinical outcome and survival of children with long-standing systemic onset juvenile idiopathic arthritis (SOJIA) and amyloidosis. 27 patients (11 male, 16 female) with SOJIA and amyloidosis had an average SOJIA duration of 17.3 yrs. The past and current status were assessed from hospital records, through a questionnaire and a personal interview of all living patients. Amyloidosis was diagnosed (histopathological methods) 1.7-20 yrs after the onset of SOJIA (mean 5.3 ±4.6 yrs). The mean follow-up from the diagnosis of amyloidosis was 11.1 ±7.0 yrs. 24 of 27 patients are currently alive (3 of 27 (11.1%) died). Infection was the cause of death in 2 patients with renal failure. One patient had undergone successful renal transplantation, and 3 had compensated renal failure. 11 (40.7%) have only abnormalities in routine urine analysis. Five of these are still on cytostatic and low dose steroid therapy and 6 are on low dose steroid therapy. Nephrotic syndrome was diagnosed in 2 patients. One patient with remission of SOJIA and proteinuria requires antihypertensive medication, one has hepatomegaly and one is still being treated with chlorambucil. Four (14.8%) are in remission (10-20 yrs) - off medications, no arthritic activity, only residual joint damage, complete remission of inflammatory activity, no signs of amyloidosis. Although amyloidosis is still a serious complication of SOJIA, prognosis is not very bad in all patients with SOJIA and amyloidosis. Mortality is lower than expected on the basis of earlier studies.