Two cases of carcinosarcoma of the lung are presented. Until now, 76 cases have been recorded in the literature. The lesion contains an epithelial and a mesenchymal component, both with cytologic features of malignancy. A central endobronchial and a peripheral invasive type have been described. Fiberoptic biopsies usually show no tumour at all or contain only one of the two components. Treatment consists of lobectomy or pneumonectomy. Prognosis is not better for this tumour than for non-small cell bronchogenic carcinoma, and may even be worse.