The congenital cystic adenomatoid malformation of the lung is a rare disease, and is one of the most common congenital lung diseases which require prompt surgical intervention. The prognosis depends on its tissue type, prompt diagnosis and surgical intervention. The lesion consists of enlarged, variable sized multiple cyst with overgrowth of terminal bronchioles, like hamartoma. This disease can be associated with other vascular anomalies or other congenital defect especially in type II lesion We recently experienced one case of congenital cystic adenomatoid malformation The patient was 2 months old infant who showed respiratory distress without associated anomaly. After right upper lobe lobectomy, the patient was recovered uneventfully.