We present an unusual case of 30-year-old man who was admitted to our hospital with dysesthesia of the limbs and skin eruptions. Polyarteritis nodosa was diagnosed based on the histopathological examination of sural nerve and renal biopsies. A month after initiation of corticosteroid therapy, a small infiltrative shadow was detected in the right mid-lung field by chest X-ray. Aspergillus infection was suspected based on a culture of bronchial lavage fluid. Despite intravenous administration of the antifungal agents, miconazole and fluconazole, a thin-walled cavity with a fungus ball gradually formed in the infiltrative lesion. The patient's clinicopathological findings were consistent with a diagnosis of chronic necrotizing pulmonary aspergillosis, a rare aspergillus infection in the lung. Treatment with intracavitary instillation of amphotericin B proved effective.