A 57-year-old woman was admitted to our hospital for lumbago, weight loss and weakness of her right lower extremity. Leukocytosis was evident with marked eosinophilia (65.5 % = 46,000/mm3), and the chest roentgenogram showed diffuse reticular shadows throughout both lung fields and a left pleural effusion. The pleural effusion contained 22.4 % eosinophils with no immature cells. Biopsy of a thumb-sized mass on the chest wall revealed a T-cell lymphoma of pleomorphic type. The diffuse pulmonary shadow was diagnosed as chronic eosinophilic pneumonia by autopsy. This was a relatively rare case of T-cell lymphoma, in which an eosinophilic pneumonia and eosinophilic pleural effusion were observed.