We report a case of idiopathic pulmonary hemosiderosis (IPH) in a three-year-old male patient who presented with severe iron deficiency anemia. The child had been diagnosed with iron deficiency anemia nine months earlier and had received multiple blood transfusions, but the cause of his anemia had not been established. The diagnosis of IPH was made after a biopsy of the left lung showed large numbers of hemosiderin-filled macrophages in the alveoli. He did not respond to standard dose corticosteroid (CS) treatment (2 mg/kg/d). However, high-dose short-term CS treatment was successful in two episodes of acute respiratory hemorrhage in this patient. We conclude that IPH should always be considered when investigating the cause of iron deficiency anemia. A more rapid diagnosis in this case could have prevented unnecessary investigations and blood transfusions. We also suggest that high-dose short-term CS treatment should be kept in mind, especially in patients who do not respond to a standard dose.