One hundred and sixty-three male and 78 female cases of lung sarcoma, registered over 29 years from 1958 to 1986, were selected and analyzed, and were compared with lung cancer cases. The incidence of the lung sarcoma cases was one per 2,600 in males and one per 3,600 in females among all autopsy cases, and one per 1,400 in males and one per 1,800 in females among all autopsied cases of fatal malignancies. The relative incidence of lung sarcoma was one per 240 lung cancer cases in males and one per 170 in females and gradually decreased with each decade (1st to 3rd periods). The male/female ratio was 2.1 overall and 2.6 in the 3rd period. In the 3 decades, the average age at detection 55, 55 and 66 years in males and 38, 51 and 49 years in female lung sarcoma cases. Female sarcoma cases were significantly younger than male cases, except for the 2nd period. In the 3rd period male cases were almost the same as lung cancer cases in terms of average age. Significant elevation was observed in lung sarcomas. The most frequent lung sarcomas in males were rhabdomyosarcoma, leiomyosarcoma, and malignant lymphoma in the 3 decades. In females, the above three sarcomas were most frequent in each chronological period. Malignant fibrous histiocytomas appeared remarkably in the 3rd period in both sexes. The peak and mean ages for each type of lung sarcoma were higher than other reports. In malignant lymphoma and rhabdomyosarcoma, male cases were significantly older than female cases.(ABSTRACT TRUNCATED AT 250 WORDS)