A 40-year-old woman with no major medical illness except for morbid obesity (BMI 40.7) was admitted to our hospital because of bilateral pneumonia due to a novel swine-origin influenza A (H1N1) virus (S-OIV). Non-invasive ventilation was introduced because of the hypoxemia. The description of bronchoalveolar lavage fluid findings showed an alveolar hemorrhage and neutrophilic inflammation. No evidence of bacterial infection was found. She was treated with oseltamivir and sivelestat sodium, neutrophil elastase inhibitor and thereafter was successfully discharged from the hospital. This case is the first report of a patient with acute lung injury with an alveolar hemorrhage caused by the S-OIV.