Patients with systemic necrotizing vasculitis frequently present as diagnostic dilemmas. In previous series of patients with polyarteritis nodosa, less than one third were diagnosed antemortem. Although current clinical awareness of systemic necrotizing vasculitis is greater than in the past and procedures for the diagnosis of these diseases have improved, patients commonly present with atypical features. The diagnosis of a systemic necrotizing vasculitis frequently remains unsuspected or unproven until an involved tissue is biopsied. We report an unusual case of systemic necrotizing vasculitis in which the diagnosis was confirmed by a transbronchial biopsy of the lung which demonstrated pulmonary capillaritis with hemorrhage.