We report the case of a 57-year-old woman with Wegener's granulomatosis who presented with otitis media. The patient presented with a 2-month history of bilateral hearing loss and dizziness. Antibiotic treatment was not effective, and the patient was confirmed to have bilateral sensorineural hearing loss. Serum was positive for cytoplasmic anti-neutrophil cytoplasmic antibody [C (PR3)-ANCA] but negative for P(MPO)-ANCA (perinuclear ANCA). While the test results were pending, the patients' general condition worsened ; in particular, signs of active inflammation, cardiorespiratory failure and scleritis developed suddenly. Emergency chest computed tomography revealed evidence of lung involvement and hydrothorax; thus, the patient was diagnosed to have the generalized form of Wegener's granulomatosis. The patient was started on pulse methylprednisolone therapy at 1000mg/day for 3 days, which resulted in marked clinical improvement, and then, the drug therapy was switched to prednisolone 60mg/day and cyclophosphamide 50mg/day and gradually tapered. Early diagnosis of Wegener's granulomatosis is often difficult because of atypical manifestations of the disease; particular attention must be paid to acute onset of the disease, such as in our case. ANCA is a very useful marker for early diagnosis, but about one week is needed to obtain the test results. We believe that early steroid and cyclophosphamide therapy is an effective therapeutic option for patients with signs of severe inflammation and generalized involvement.