We report a case of recurrent pulmonary infections in a 14 years old patient with an abnormal chest x-ray. The patient was admitted to our department with a high fever, for which she was treated in another hospital. The chest x-ray was abnormal, with a shadow of the left upper lobe and emphysematous hyperinflation of the left lower lobe. After a conservative treatment with the administration of wide spectrum antibiotics and physiotherapy, the patient became free of fever, while the chest x-ray showed the remaining mass of the left upper lobe, with the organs of the mediastinum in normal position and without the existence of emphysema of the lower lobe. Chest CT Scan, revealed the existence of a huge mass of the left upper lobe, with a tumor mass into the left main bronchus. Also there were enlarged mediastinal lymph nodes and a suspicion of mediastinal infiltration caused by the tumor mass. Bronchoscopy showed an endobronchial mass that caused a 90% obstruction of the left main bronchus lumen. The patient underwent a left anterior mediastinotomy (Chamberlain procedure), which demonstrated the absence of mediastinal infiltration. A left posterolateral thoracotomy followed, and a sleeve left upper lobectomy was performed. The postoperative course was uneventful. Histology examination confirmed the diagnosis of pulmonary blastoma. This rare tumor is called adenocarcinoma of embryonic type, it represents less than 1% of all lung tumors and is characterized by poor prognosis. Pneumon 2004, 17(3):341-344.