A non-smoking 76-year-old woman was admitted to our hospital complaining of cough, bloodstained sputum and difficulty in breathing that had developed while she was eating a meal. The initial diagnosis was upper airway obstruction. Her past history revealed no major illness, except that she was under medication for the treatment of hypertension. On examination, chest radiography and computed tomography (CT) scans showed diffuse ground glass opacities in both lungs, and bronchoalveolar lavage studies further yielded findings compatible with pulmonary hemorrhage. The patient's symptoms and hypoxemia improved gradually without any specific treatment. Laboratory data showed no specific underlying cause, such as vasculitis or collagen vascular disease, for the pulmonary hemorrhage. We therefore reached a diagnosis of a negative pressure pulmonary hemorrhage (NPPH) caused by upper airway obstruction. Follow-up examinations after 7 months showed no abnormal findings in the chest radiography or arterial blood gas analysis. To our knowledge, this is the first case of negative pressure pulmonary hemorrhage in japan.