Five cases of primary chondrosarcoma, a rare tumor of the lung, are reported. The diagnosis should be made by pathology. Some conditions should be ruled out: 1. tumor from the chest wall, 2. chondrosarcoma of bone discovered after operation, 3. ovarian teratoma found prior to operation, 4. patient with history of hamartoma of the lung, and 5. atypical pathology. Pathologic subtyping is not prognostic. The main cause of death was intralobar spread. It never gives rise to extrathoracic metastasis and should be treated by surgery.