Lethal midline granuloma is a rare disease of unknown etiology characterized by ulcerative, necrotic lesion of the upper respiratory tract, progressive pulmonary and renal involvement, and death in a period four to five months. Diagnosis could be made by biopsy of upper respiratory tract in early stage and needle biopsy of kidney in a late, and was confirmed often at autopsy. In regard to treatment, recently, long-term and massive administration of corticosteroid, small dosage of radiation, chemotherapy could be tried, however, not stopped progression. The authors, recently, have observed 3 cases (male, 33 yrs., 36 yrs., 40 yrs.) of lethal midline granuloma which was confirmed as pathologically. Under the treatment of long term, massive administration of prednisolone, gamma-globulin injection, tubercin-C vaccination, a little improvement of disease was made.