Pulmonary sarcoma is a rare tumor of the lung. There are 81 cases in the literature for review, including our two cases. Our first case who was a thirty-seven year old male who was admitted to our hospital with complaints of left back pain. His chest X-ray showed an 11 X 14 cm tumor shadow in the lower left lung area. A left upper lobectomy was performed, and the histological diagnosis was leiomyosarcoma of the pulmonary vein. He died due to mediastinal recurrence 29 months later. Our other case was a fifty-six year old female. Her chest X-ray showed an abnormal shadow that was a tumor shadow in the right central lung area of 4 cm in diameter. As the diagnosis of the transcutaneous lung biopsy was benign tumor, partial resection of lung was performed. The histological diagnosis was leiomyosarcoma of the bronchus, and she is alive and well at 29 months after the operation. As the rate of diagnosis in leiomyosarcoma detected by transcutaneous lung biopsy is low, the most acceptable method of diagnosis is a total examination, including cytology of sputum, bronchoscopic findings, and roentgenoscopy. Probe thoracotomy would also be necessary if malignancy could not ruled out. The treatment of lobectomy should include lymph node resection.