Congenital alveolar dysplasia (СAD) and alveolar capillary dysplasia with misalignment of the pulmonary veins (ACD/MPV) are rare genetically determined interstitial lung diseases in infants that manifest in the first hours to days after birth, have fatal outcome and are usually diagnosed at autopsy.The aim of this work was to consider the clinical manifestations and pathomorphologic picture of CAD and ACD/MPV based on clinical observations of newborns who were on a ventilator, received therapy for high pulmonary hypertension and extracorporeal membrane oxygenation (ECMO). The clinical characteristics and medical history of the patients are described. The results of lifetime imaging methods, autopsy examinations with light microscopy and the use of routine staining methods of micro-preparations as well as immunohistochemical methods are considered. Morphologic changes in the lungs characteristic of CAD and ACD/MPV are described in detail in the analysis of histologic examination data.Conclusion. The pathoanatomical examination data are of crucial importance for the diagnosis of CAD and ACD/MPV, which must be suspected in newborns with respiratory insufficiency and severe pulmonary hypertension when ventilation, inhalation of nitric oxide and ECMO are ineffective.