Background: Congenital bronchogenic cyst is a well-known but rare congenital malformation of the respiratory system. The origin of isolated cysts relates to the pseudoglandular phase of lung development (7th-16th week of gestation). This malformation can be diagnosed in radiological examinations in neonate as a single cyst in lungs situated peripherally or in mediastinum projection. The goal of our study was to establish diagnostic and clinical criteria for congenital bronchogenic cyst in neonates and children, based on postnatal diagnostics in our center. Material/Methods: We analyzed 4 cases of patients with congenital bronchogenic cyst, who were diagnosed and/or treated in the Department of Neonatology at the Polish Mother's Memorial Hospital Research Institute from 1 January 1991 do 31 March 2005. The diagnosis was established based on the clinical picture of the malformation, a chest x-ray, computed tomography of the lungs of the neonate, and pathological examination. After discharge from the Department, the neonates remained under the care of many specialists from our Institute in order to maintain follow-up. Results: In years 1991-2005 the diagnosis of congenital bronchogenic cyst was established in 4 patients treated in our Department. In these 4 cases, the diagnosis was established based on radiological diagnostics (chest x-ray and computed tomography of the lungs) and three of the four were confirmed by pathological exam. The differential diagnosis covered congenital cystic adenomatoid malformation of lungs (CCAM), enterogenic cysts, bronchopulmonary sequestration, congenital lobar emphysema, diaphragmatic hernia, and pneumothorax. Conclusions: Radiological diagnosis in neonates with congenital bronchogenic cyst is essential, because it allows us to obtain genuine data regarding this malformation in the population. Neonates diagnosed with congenital bronchogenic cyst should be monitored in a tertiary referral center. Our patients with a diagnosis of congenital bronchogenic cyst after successful surgery show normal psycho-physical development in follow-up, and none showed any disturbances in the circulatory system.