Radiographic, surgical and pathological features of 33 paediatric patients with bronchogenic cysts are reviewed. These congenital lesions usually presented as spheroid mediastinal masses, near the carina or right paratracheal area, 2-3 cm in diameter with sharply delineated borders. Occasionally, the masses were lobulated or triangular in shape. Some cysts produced considerable airway distortion. All intrapulmonary cysts had connections, sometimes patent, with the trachea or main-stem bronchi. Thin-walled, completely aerated cysts became thick-walled with infection. A few air-filled and solid cysts grew rapidly. Cystic lung disease distal to central bronchogenic cysts was observed.