A case of primary chondrosarcoma of the lung is presented. The tumor, located in the medial segment of the right lower lobe, was successfully resected surgically. Clinical survey did not reveal any primary lesion elsewhere. The tumor consisted of myxomatous, chondromatous, and fibrous lesions. Immunohistochemical study revealed that tumor cells were positive for S-100 protein and vimentin, and negative for other antisera which characterize epithelial tumors. With these clinical, histological, and immunohistochemical studies we diagnosed the tumor as a primary chondrosarcoma of the lung.