Multicentric Castleman's disease is characterized by a peculiar multicentric form of lymph node hyperplasia. This report describes a 53-year-old female patient with multicentric Castleman's disease admitted because of generalized lymphadenopathy, including palatine tonsils and adenoids. A CT scan showed well-enhanced masses in cervical, chest and abdomen. Although malignant lymphoma was suspected, based on clinical features, malignant histological findings were not observed in the tonsils. However, the cervical lymphnode showed angiofollicular hyperplasia of the hyaline-vascular type, and the patient was diagnosed with Castleman's disease. A bilateral tonsilectomy and adenoidectomy were perf omed under general anesthesia to relieve the patient's symptoms of nasal stiffness and dyspnea. After surgery, oral prednisolon (60mg) administrated was perfomed daily for 3 weeks, after which the dosage was gradually decreased. After daily oral administration of prednisolon, the multicentric lymphadenopathy almost completely disappeared. Clinical examination showed an increased level of IL-6 in the patient's serum before tonsillectomy and IL-6 positive cells were detected by immunohistological staining of the tonsils. These findings indicate that IL-6 is associated with this disease. The prognosis with this disease is poor, and frequently the patients die rapidly of septicemia or other infections. Since this disorder in some patients is complicated by malignancies, special attention should be paid in observing the course of this disease.