We report a case of a woman who at age 58 had an operation on the right femur for malignant fibrous histiocytoma (MFH). At age 63, a chest X-ray examination disclosed a tumor shadow, for which we suspected metastasis from the MFH. Chest computed tomography showed that the tumor had infiltrated to the left atrium via the pulmonary vein. We operated on the patient, first dividing the arterial supply to the lower lobe, and then opening the pericardium. We blocked the lower pulmonary vein and left atrium with a Cooley-Dera clamp and resected the tumor. The tumor was polypoid and had invaded the left atrium. Fifteen months after this lung surgery, the patient was diagnosed with a brain tumor, which was resected. Invasive primary lung cancer to the left atrium via the pulmonary vein is common, but metastasis from a sarcoma such as MFH to the left atrium via the pulmonary vein is extremely rare.