Goodpasture's syndrome (GPS) is managed by a combination of steroids, cyclophosphamide, and plasmapheresis, but the optimal therapy for mild cases is uncertain. A 45-year-old woman who had a 3-month history of cough and hemosputum visited our hospital. Chest CT revealed slight bilateral ground-glass opacity. In biochemistry views, anti-GBM antibodies were positive, and uric blood was also. Therefore the patient was diagnosed with GPS. On the first hospital day, bronchoscopy was performed to confirm alveolar hemorrhage, and steroid pulse therapy was then done. On the third hospital day, the patient developed respiratory failure as a result of a rapidly worsening alveolar hemorrhage. Administration of cyclophosphamide and plasmapheresis on steroid therapy induced remission. Our case suggested the importance of plasmapheresis combined with steroids and cyclophosphamide for the treatment of mild cases of GPS.