A thalassaemic girl presented with agranulocytosis, arthritis of both ankles and clinical and laboratory features consistent with the diagnosis of systemic vasculitis, during oral iron chelator L1 (deferiprone) treatment. Changes in the humoral and cell-mediated immune function. including antinuclear antibodies (ANA), anti-DNA and extractable-nuclear antigens (ENA) antibodies positivity, increased immunoglobulin values, decreased T suppressor and the presence of circulating immune complexes, suggest a cause-and-effect relationship with the observed clinical manifestations. A careful monitoring of the immune function is recommended in patients who are receiving the oral iron chelator L1.