Congenital cystic adenomatoid malformation [CCAM] of the lung is a rare but often fatal congenital lung bud anomaly that causes acute respiratory distress in the newborn infants. In those who survive infancy and early childhood, its clinical manifestations are not unusual to detect. Recently we experienced two children with CCAM; one with coughing and high fever, another without any symptom On case I, the patient was a 9 year-old female, and was suffered from coughing and high fever since 15 days before. Medical treatment was failed and then, exploratory thoracotomy was performed under the impression of loculated empyema. Finally, a right lower lobectomy was done with a satisfactory postoperative course. On case II, the patient was a 12 year-old female, and admitted for evaluation of known large pulmonary cyst which was checked at the outpatient clinic. Preoperative evaluations gave no more informations, so obliteration of cysts was performed with open biopsy. Two patients with CCAM are described in Korean Univ. Medical Center.