Congenital cystic adenomatoid malformations (CAMs) are rare lung lesions characterized by the presence of a multicystic mass of pulmonary tissue. To clarify the surgical management of CAM of the lung, we reviewed our institutional experience with 34 patients with histologically documented CAM. Symptoms developed in the first 2 days of life in 20 patients; 14 patients developed symptoms a median of 69 days (range, 22 days to 15 years) after birth. A diagnosis of CAM was confirmed at thoracotomy in all patients. Four patients were treated with a limited pulmonary resection for disease confined to one lobe. Seven patients underwent a composite resection involving a lobectomy plus limited resection of the second lobe. One patient underwent pneumonectomy for a severely malformed lung. The remainder of the patients were treated with anatomic lobectomy. The only recurrence was a patient who had a partial cystectomy performed at the initial operation. We conclude that in the appropriate malformation subtype, limited pulmonary reactions can preserve lung tissue and may prevent subsequent complications of CAM.