A 19-year-old woman was admitted to Kushiro city general hospital due to chest pain and dyspnea. Chest radiographs and computed tomographic scan showed a large intrathoracic mass adjacent to the pleura. Angiographs disclosed feeding veins of the tumor arising from lateral thoracic artery. Fine-needle aspiration cytology of the tumor revealed small round cells with a large nuclear/cytoplasmic ratio. Immunocytochemical study demonstrated that the tumor cells were positive for neuron-specific enolase and MIC 2 gene product. The diagnosis was primitive neuroectodermal tumor of the parietal pleura (also known as Askin tumor). Chemotherapy combined with peripheral blood stem cell transplantation reduced the size of the tumor significantly. However, multiple bone metastasis recurred, and the patient died 35 months after the start of therapy.