A Wegener's granulomatosis is a rare disease of unknown etiology, characterized by focal necrotic vasculitis in upper or lower respiratory tract, lung, kidney, skin and joints. Diagnosis can be made by biopsy of nasal cavity, kidney and lungs, and clinical signs of characteristic granuloma and giant cells with wide spread vasculitis. Kideney biopsy showed glomerulonephrits and vasculitis. In regard to treatment, recently longterm and massive administration of corticosteroid, small dose of irradiation and cytotoxic drugs could be tried, however did not show stopped progression of disease. Authors have observed 3 cases of Wegener's granulomatosis which was pathologically confimed and treated those patients with steroid and chemotherapy. So authors report above 3 cases with references.