In patients with yellow nail syndrome (YNS), highly characteristic nail changes are often associated with lymphedema and respiratory disorders due to pleural effusions or bronchiectasis. We describe a 4-year-old girl with the YNS who also had cystic lesions of the lung, affecting first the left lower lobe and, after surgical resection of the involved segments, also the right lower lobe. We discuss the etiology of the pulmonary cysts and hypothesize that abnormalities in pulmonary lymphatic flow, characteristic of YNS, may have decreased lung tissue compliance and determined the unusual progression of the cystic lesions in this patient.