A retrospective study of 79 juvenile arthritic patients with reactive amyloidosis for a mean of 10 years (3 months-24.25 years) from the onset of amyloidosis was performed. Eighty percent of those treated with chlorambucil (n = 57) were alive compared with 23.5% of patients not treated with chlorambucil (n = 19) 10 years after diagnosis. Renal failure was the cause of death in 82.3% and infection in 11.7%. Side effects included one chlorambucil-treated patient who developed acute leukaemia, and seven patients who developed severe leucopenia and four thrombocytopenia. Fifteen patients are no longer on cytotoxic therapy and are in remission. Analysis of their fertility status showed that there were 5 normal births in 3 women and 2 terminations of pregnancy in 23 chlorambucil-treated women of child bearing age. Six women had ovarian failure. None of the male patients fathered a child.