Hypereosinophilic syndrome is a spectrum of disorders characterized by marked eosinophilia of no identifiable cause and by organ dysfunction. In 1999, a patient with marked weight loss, eosinophilia and a hypodense lesion in the right lobe of the liver was diagnosed as hypereosinophilic syndrome by fine needle aspiration biopsy and bone marrow aspiration biopsy. Echocardiography and thoracal HRCT was found to be normal. The patient was prescribed 30 mg prednisolone daily with the dose being tapered gradually. At the end of treatment, computerized tomography was normal but ultrasonography showed a 1mm x 3mm lesion. Liver scintigraphy was then performed in order to determine the activity of the lesion and was found to be normal. The lesion was therefore thought to be from a previous infection.