Bronchogenic cysts are rare congenital malformations that occur in adults and children, with differences in distribution and presentation. We present the case of a newborn who initiated respiratory distress from the first minutes of life, presenting with hypoventilation and rightward displacement of the cardiac impulse, requiring oxygen therapy and intubation. The first radiograph shows a left pulmonary emphysema. The computerized axial tomography revealed a large mediastinal mass causing an obstructive syndrome of the left bronchus. The mass was successfully excised, resulting in a favorable clinical evolution. Although the presentation of our case is exceptional, it is worth noting that while most bronchogenic cysts are asymptomatic, they can occur in childhood, even from birth, as in our case.