Combined type of primary lung cancer is a very rare form in clinical experience, which is 3 histologically different variants of bronchogenic carcinoma. These type had a well differentiated squamous carcinoma forming keratin pearls, well differentiated adenocarcinoma and pleomorphic undifferentiated cell carcinoma, usually small cell carcinoma. The patient, a male, 49-Y-0, was complaint coughing, mild dyspnea, blood tinged sputum and chest pain. Under diagnosis of lung cancer preoperatively, the right total pneumonectomy was performed with very difficulty such as arrhythmia, ventilation impairment during post operation course. The histology of specimen was disclose as 3 different histological type, combined lung cancer as squamoadenoundifferentiated carcinoma. The mediastinal nodes were freed from metastasis but the parietal pleural metastatic loci was found. The radio & chemotherapy were performed post-operatively. The patient had been experienced empyema at post-pneumonectomy space and then open drainage procedure and thoracoplasty had been added for treatment course. The patient is alive recently. [KTCS 1983;3:368-374]