Idiopathic thrombocytopenic purpura (ITP) is a hemorrhagic disease that often occurs in the elderly. It generally presents as a chronic disease with insidious onset, and is frequently resistant to various therapies. Compared to patients less than 40 years old, those older than 60 years tend to show a higher rate of ITP-related mortality. The present report describes a 73-year-old patient with acute ITP who experienced diffuse alveolar hemorrhage that responded well to high-dose intravenous immunoglobulin therapy combined with corticosteroid pulse therapy.