Acute massive pulmonary hemorrhage is described as part of the clinical picture of SLE. Seven patients had sudden onset of high fever, dyspnea, tachycardia, and cough with blood-tinged sputum that within hours progressed to massive hemoptysis and death. There were no vasculitis or other inflammatory lung changes found at autopsy. Only one of the seven reported cases survived when treated with 2 g of intravenous hydrocortisone daily. The mechanism of this pulmonary bleeding is unknown but seems to be an immune complex mediated phenomenon.