It has been reported that various organs are involved in idiopathic hypereosinophilic syndrome. Frequently, the heart, lung, skin, and nervous system are involved. Involvement of the middle ear, however, has not yet been reported. In this article, the authors describe the first case of hypereosinophilic syndrome involving the lung and middle ear. A 39-year-old woman had a 4-month history of low grade fever, non-productive cough, and a feeling of fullness and hearing loss in both ears. Peripheral blood cell count showed eosinophilia. Bilateral tympanic cavities were obstructed with granulation tissue, and she was diagnosed as obliterative otitis media. The granulation tissue consisted of foamy histiocytes and eosinophils. Chest X-ray film and computed tomography showed patchy infiltrative shadow in the lung. Histologic examination of the open lung biopsied specimen showed alveolar spaces infiltrated by eosinophils. After treatment with 30 mg oral prednisolone daily, there was a rapid improvement in her clinical condition. Based on the clinical course and the histologic findings of this case, obliterative otitis media may be caused by eosinophilic infiltration and eosinophilic pneumonia.