Pulmonary angiosarcomas are usually secondary tumors, and only a few primary cases have been reported. Effective strategies for treating this tumor have not been established, and the prognosis of affected individuals is generally very poor. We report a case of primary angiosarcoma presenting as a hemorrhagic solitary nodule at the bifurcation of the left main bronchus, followed for two years before surgery. Bronchial arteriography revealed a tumor stain sign, and racemose hemangioma of the bronchial artery was excluded. The hemoptysis was not controlled by repeated bronchial artery embolization, and the patient underwent left pneumonectomy with routine mediastinal lymph node dissection. Histopathologically, the excised tissue revealed a highly-cellular growth of atypical spindle cells with a storiform pattern. These atypical cells showed relatively low mitotic activity; the MIB-1 index was 10%. The tumor was diagnosed as a primary angiosarcoma of the lung by the following immunohistological findings: positivity for factor VIII-related antigen and CD31. One year after resection, the patient remains well without signs of recurrence.