Unilateral congenital pulmonary lymphangiectasia (CPL) is an extremely rare disease of the pulmonary lymphatic vessels. Objective: to present a case of CPL in a premature newborn. Clinical case: premature male newborn with severe respiratory failure at 2 hours of extrauterine life was treated with exogenous surfactant, catecholamines and high frequency oscillatory ventilation (HFOV). Chest computed tomography (CT) scan showed bullae and air trapping of the left lung; the histopathological study showed cystic dilation of the bronchoalveolar lymphatic channels. The diagnosis of secondary unilateral CPL was made. The clinical course up to 19 months of age was normal and the chest CT scan showed few emphysematous bullae. Conclusions: CPL must be one of the differential diagnoses in neonates with unexplained respiratory distress. The prognosis will depend on the type of CPL and lung involvement