The case was a foully years old man who was admitted with complaints of left chest pain and dyspnea. X-ray of the chest revealed a relatively round and well defined mass shadow in the left lower lobe of the lung. Left lower lobectomy was performed under the diagnosis of a tumor. Grossly, a large, soft, necrotic and friable tumor wart located at the peripheral portion of the lobe. No encapsulation was noted tut the border was relatively well demarcated. Microscopically, the tumor was composed of tubular and glandular epithelial component and spindle-shaped stromal element. Both element exhibited malignant nature. The Picture looked like a carcinosarcoma on one hand, and reminiscent to developing fetal lung one the other hand. After reviewing of the literature, the lesion is best considered to a case of pulmonary blastoma which differ in prognosis from carcinosarcoma.