Erdheim-Chester disease (ECD) is a rare systemic non-Langerhans histiocytosis that affects multiple organ systems. It occurs more often in adults, and paediatric ECD is extremely rare. The diagnosis of ECD can be established based on clinical presentations and imaging but the final diagnosis should be based on biopsy. Treatment of ECD has involved the use of corticosteroids, radiotherapy, chemotherapy, surgery and haematopoietic stem cell transplantation, yet the efficacy of these treatments is difficult to determine. At present, it is thought that the treatment of interferon-α (IFN-α) is safe and effective for ECD. Herein, we report on an 11-year old girl who was admitted to hospital because of systemic bone pain and limping, and the final diagnosis of ECD was based on evidence provided by her clinical presentation, imaging and biopsy of a lesion of the right ilium. The patient was treated with subcutaneous IFN-α at a dosage of 3 × 106 units three times weekly for 19 months. We thought that the treatment of IFN-α was safe and effective for the girl’s clinical manifestations, and IFN-α might be a valuable first-line therapy for paediatric ECD.