Pleuropulmonary blastoma is a rare childhood malignancy that may simulate an empyema both clinically and radiographically. A 3-year-old boy with fever, cough, and abdominal pain developed complete opacification of the left hemithorax with contralateral mediastinal shift over the course of several weeks. At thoracotomy, a pleuropulmonary blastoma was discovered. The radiology, pathology, and clinical course of this rare neoplasm are discussed.