In a 52-year-old man, chronic eosinophilic pneumonia (CEP), suggested by clinical history and marked eosinophilia in the peripheral blood and in the bronchoalveolar lavage fluid, has been diagnosed on open lung biopsy. Nevertheless, chest roentgenograms never showed any infiltration during the course of the disease. Extensive etiologic examination remained negative. Steroid therapy induced a dramatic clinical response, disappearance of the eosinophilia in the peripheral blood and in the bronchoalveolar lavage fluid, and quick normalization of pulmonary function. We suggest that a typical history and markedly eosinophilic alveolitis allows one to make the diagnosis of CEP even in the presence of normal chest film findings.