Pleomorphic (spindle) cell carcinoma, also known as monophasic sarcomatoid carcinoma, is a rare primary pulmonary malignancy. This type of tumor shows concurrent presence of malignant epithelial and homologous sarcomatoid spindle cell components by co-expressing cytokeratin and vimentin in various degrees. Sixteen cases (four central endobronchial lesions and 12 peripheral parenchymal masses) were studied clinicopathologically. Men were affected far more frequently than women (13:3). The patients were between 56 and 80 years of age. The disease is strongly associated with smoking. Among seven of the patients who underwent surgical resection, four of them had mediastinum, pleura and chest wall invasions, and three of them had regional lymph node metastases. All of the patients succumbed to early distant metastases (range 2 weeks-5 months) in organs including brain, bone, adrenal gland, and unusual sites such as esophagus, jejunum, rectum and kidney. The remaining nine inoperable cases were late stage disease and treated with chemoradiotherapy with little effect. The median duration of survival was 3 months. All parenchymal masses appeared as cavities with marked central necrosis, and only peripheral rim of tumor cells was left. More definite diagnostic results will depend on further tissue sections and can be confirmed by immunohistochemical studies. Significantly fewer Ki-67, p53 and c-erb B-2 oncoprotein expressions were also noted.