A 53-year-old man was admitted to our hospital because of an abnormal lung shadow on his chest X-ray film. His symptoms were cough and shortness of breath. Chest X-ray and computed tomography showed a large mass lesion in the right lower lobe of the lung. We diagnosed primary non-small cell lung cancer; cT3N1M1 stage IV. Systemic chemotherapy using carboplatin and paclitaxcel was performed. However, the treatment had no effect and he died two months after admission. An autopsy showed pulmonary spindle cell carcinoma, with multiple metastases to the brain, pancreas, etc. Pulmonary spindle cell carcinoma had been recognized as a variant of the squamous cell carcinoma for years, however, in the recent WHO and Japanese classification of lung tumors, it was redefined as an independent histological type. It is a rare form of lung cancer, representing 0.2 to 0.3% of all primary pulmonary malignancies and seems to have poor prognosis. We need to pay more attention to this type of lung cancer.