A 9-year-old and a 17-year-old male patients affected by metastatic Ewing sarcoma developed an organizing pneumonia after high-dose chemotherapy with autologous peripheral blood stem cell transplantation followed by total-lung irradiation. They were successfully treated with high-dose corticosteroid for 6 months slowly tapered, with a significant clinical and radiologic response. Organizing pneumonia is a nonspecific response to various forms of lung injury such as high-dose chemotherapy and radiotherapy. For this reason, even if rare, has to be considered in children affected by lung metastatic Ewing sarcoma with persisting pulmonary symptoms after peripheral blood stem cell transplantation and total-lung irradiation. This report provides a useful description for the evaluation and treatment of pediatric patients with pulmonary infiltrates after chemotherapy and radiotherapy.