A 39-year-old male was admitted to Dept. of Thoracic Cardiovasc. Surgery, Korea University Hospital with the chief complaints of progressively enlarged mass on right upper lung which revealed on routine chest P-A since 4 Years ago. Chest PA and tomography revealed well circumscribed huge mass of 7cm. in diameter without invasion on bronchus. so, right upper lobectomy was performed under impression of lung cancer. Postoperative pathologic examination revealed pulmonary blastoma. Pulmonary blastoma is accepted as a distinctive neoplasm recently. One case of typical pulmonary blastoma is reported, and the previous literature is reviewed. There are no specific clinical or radiologic feature of pulmonary blastoma. The presentation is can be that of any other pulmonary tumor although a peripheral situation is usual and a large size is often attained before detection. Pulmonary blastoma is a mixed tumor with malignant epithelial and connective tissue components with a distinctive resemblance to fetal lung. The treatment of choice is surgical excision but the overall prognosis is poor. There is no evidence of recurrence or metastasis on follow-up study during 6 months period after right upper lobectomy. [KTCS 1981;2:127-130]