A 32-year-old man was referred to our hospital because of a nodular shadow on his chest x-ray film. Chest computed tomography scan revealed multiple nodules in both lungs. Video-assisted thoracoscopic surgery was performed to diagnose the tumor. Microscopic examination of the resected specimen showed tumor connecting of small round cells. Fluorodeoxyglucose positron emission tomography demonstrated strongly increased uptake in the right femur. Subsequently, magnetic resonance imaging showed a well defined mass, approximately 5 cm in diameter, in the right lateral femur with isointensity on T1-weighted images and high intensity on T2-weighted images. A needle biopsy of the tumor of the right femur was performed. Pathological examination revealed the same findings of the pulmonary lesions. Immunohistochemical staining was positive for CD99 in the tumor cells. Ewing's sarcoma gene rearrangement was found using fluorescence in situ hybridization on frozen-section specimens. Based on these findings, a diagnosis of Ewing's sarcoma was made. The patient died 13 months after the initial detection of the disease despite intensive chemotherapy. In cases of multiple pulmonary nodular lesions in a young patient, metastatic tumors arising from bone soft tissue should be included in the differential diagnosis.