Pulmonary hemosiderosis is characterised by repeated episodes of intra-alveolar haemorrhage that lead to abnormal accumulation of iron as hemosiderin in alveolar macrophages and subsequent development of pulmonary fibrosis and severe anaemia. Pulmonary hemosiderosis can occur as primary disease of the lungs, e.g. idiopathic pulmonary hemosiderosis, or can be secondary to cardiovascular or inflammatory connective tissue diseases. We present the case of a girl suffering from idiopathic pulmonary hemosiderosis. At the age of 15, after influenza infection, she developed juvenile lupus erythematosus. We describe diagnostic difficoulties and complications of treatment.