Congenital cystic adenomatoid malformations of the fetal lung (CCAM) are rare embryonic developmental abnormalities. They are considered as benign hamartomatous or dysplastic lung tumors characterized by overgrowth of the terminal respiratory bronchioles at the expense of the saccular spaces. A minority of cases may not be identified by prenatal imaging techniques and the pulmonary lesions are recognized postnatally. Two cases of congenital cystic adenomatoid malformation of the fetal lung diagnosed in our institution during the last four years are reported. The ultrasonographic and pathologic findings of these cases are discussed.