A 43-year-old man was admitted to our hospital because of cough and dyspnea. His chest X-ray showed bilateral basal infiltrative shadows. The increased eosinophils in BAL suggested chronic eosinophilic pneumonia (CEP), whereas the TBLB specimens showed findings compatible with desquamative interstitial pneumonia (DIP). The open lung biopsy specimens showed typical findings of DIP with a peripheral zone, suggestive of CEP. These two diseases may be only phasal differences of reaction to the same extrinsic stimulation.