The radiologic features of 18 children admitted to Princess Mary Hospital, Auckland, New Zealand, in the winter and spring of 1977 with adenovirus 21 infection are reported. Attention is drawn to the severity of the disease in the respiratory tract, manifest radiologically as widespread patchy or confluent pulmonary opacification, extensive bronchial wall thickening, or peribronchial linear opacities. No hilar adenopathy was present. Prominent residual bronchopulmonary abnormalities were present in 13 of 15 patients 6--12 months after epidemic. High kilovoltage chester radiography or bronchography demonstrated bronchiectasis in five patients. These findings emphasize the role of adenovirus as a cause of chronic pulmonary disease and bronchiectasis in children.