Desferrioxamine was used to treat six patients who had rheumatoid arthritis refractory to conventional treatment, on the basis that levels of intra-articular iron would be reduced and inflammation lessened. After a period of initial intensive treatment which was limited by side effects, five patients continued on once-weekly maintenance doses. Two patients had temporary improvement in their symptoms, but relapsed in spite of continuing treatment. The remaining three patients completed six months of treatment with no improvement in their rheumatoid disease. There were no significant changes in rheumatological parameters, immunological markers of disease activity nor radiological evidence of improvement. Treatment did lead to significant falls in haemoglobin concentration (p less than 0.01), mean corpuscular volume (p less than 0.05) and serum ferritin levels (p less than 0.02). Therefore, in spite of a reduction in iron available for haem synthesis and a fall in tissue storage iron the rheumatoid inflammatory process persisted.