A 78-year-old woman with severe auditory disturbance was referred to our hospital and was diagnosed with otitis media with anti-neutrophil cytoplasmic antibody -associated vasculitis (OMAAV). The auditory disturbance improved moderately with prednisolone 40 mg/day, but multiple pulmonary masses were detected on chest computed tomography six months later. Transbronchial lung biopsy revealed granulomatosis with polyangiitis (GPA). Administration of prednisolone 50 mg/day and cyclophosphamide 500 mg once every two weeks for 12 weeks improved the lung lesions, but no further improvement in the hearing ability was observed. Prednisolone monotherapy was not able to prevent progression of OMAAV to GPA.