Wegeners granulomatosis is a disease of unknown etiology that always involves die lungs or upper airways. In 85 percent of cases, the kidneys are affected by glomerulonephritis. The histopathologic diagnosis of Wegeners disease requires demonstration of both necrotizing granulomas and vasculitis. Open lung biopsy is usually performed in suspected disease because it is believed that a large sample of lung is needed both to demonstrate granulomatous vasculitis and to rule out other disease. Trans-bronchial lung biopsy is a less morbid procedure than open lung biopsy, but there is little information published about its usefulness in the diagnosis of this disease. We performed transbronchial biopsies through the fiberoptic bronchoscope in a patient with cavitary lung disease and obtained tissue diagnostic of Wegeners granulomatosis.