Numerous causes exist for disturbances in pulmonary ventilation in the newborn and infant. Amongst the exobronchic causes, those of cardiovascular origin are not rare. The difficulty in radiological diagnosis varies in relation with the anatomo-radiological appearance of the lesions and their aetiology. Ventilation disturbances are not always obvious. Simple techniques (high penetration films, oblique views, films in inspiration and expiration) make possible the topographical localisation of the lesions and the detection of any obstructive factor. These films should also be adequate as far as the aetiological diagnosis is concerned: severe left-right shunt, pulmonary valve agenesis, fibro-elastosis, retrotracheal left pulmonary artery. Obviously, angiocardiography is often necessary to confirm and accurately determine the nature of the "cardiovascular" lesion responsible. Such disturbances of pulmonary ventilation may either reveal or complicate a cardiac or vascular disorder in the newborn or infant. They often present marked therapeutic problems.