From January 1994 to April 1997, four patients with congenital cystic adenomatoid malformation (CCAM) underwent surgical treatment in the Department of Surgery, National Cheng Kung University hospital. Three patients were newborns and the other one is a three and half years old girl. One of them had associated with hydrops fetalis. Two newborns presented with respiratory distress. Chest roentgenography of them revealed solid mass on the left lower lung with severe mediastinal shift. One child presented with unresolved pneumonic patch on the right lower lung. Her computed tomography (CT) revealed multiple cystic lesions in the lower lobe of right lung. Chest film of the fourth patient revealed a lesion with multiple tiny cysts on the left lower lobe. Three patients survived after the surgical intervention. They were well in the follow-up of more than one and a half years. The patient associated with hydrops fetalis died of sepsis on the 20th postoperative day. The surgical procedures consisted of three left lower lobectomies and one right lower lobectomy. Pathological examination of the resected specimens confirmed CCAM, one type II and three type III. Prompt diagnosis and treatment of patients with CCAM provided good results.