We describe a case of 63-year-old woman with pulmonary artery sarcoma successfully treated with chemotherapy. She developed acute shortness of breath, and left chest and shoulder pain. Although a diagnosis of acute pulmonary embolism was made at a local hospital and she received anticoagulation and thrombolysis therapy, no improvement was achieved. Thereafter, she underwent a pulmonary thromboectomy in our hospital, and the histological diagnosis was intimal sarcoma of the pulmonary artery. Since post-operative computed tomography (CT) scans of the chest showed obvious persistence of an intraluminal hypoattenuated area in the left main pulmonary artery, the patient was treated with four cycles of a doublet chemotherapy consisting of ifosfamide (2.5 g/m(2)/day) on days 1-5 and epirubicin (45 mg/m(2)/day) on days 2 and 3. CT scans of the chest after four cycles showed marked regression of the intraluminal hypoattenuated area in the left main pulmonary artery. This is the first case of pulmonary artery sarcoma responding to chemotherapy. Surgical resection is currently the most hopeful treatment for pulmonary artery sarcoma. However, intensive chemotherapy is worth trying in unresectable patients.