In the case of a newborn affected by severe respiratory distress and anasarca, the pre-natal ultrasonography (US) was evaluated while chest plain film, GI series study, thoraco-abdominal US and computed tomography (CT) were performed at birth. Radiographic examination showed a mass lesion with signs of an associated shift. Pre and postnatal findings of a congenital cystic adenomatoid malformation (CCAM) of the lung included maternal hydramnios, fetal anasarca and a cystic or solid mass in the chest. The lobulated mass contained both fluid and air. After birth the air-filled cysts tended to be most evident. US findings appeared as single or multiple cysts involving an entire pulmonary lobe. The pericystic tissue appeared hyperechogenic. The reported case shows the contribution of the different imaging techniques in the pre-natal and post-natal sequential diagnostic imaging. CT has proved to be the method of choice in planning surgical treatment.