This chapter discusses the diagnosis, evaluation and management of massive hemoptysis. Worldwide, tuberculosis (TB) is the most common cause of massive hemoptysis. In the United States, patients frequently have a history of pulmonary disease and/or smoking, cancer, prior hemoptysis, immunosuppression, cardiac disease, or coagulopathy/anticoagulant use. Patients may present with a sentinel bleed, with only a small amount of initial hemoptysis. The clinical course of these patients is difficult to predict, as small amounts of hemoptysis may suddenly become massive. Patients may present to the ED in extremis with active hemorrhage and respiratory failure. If the patient does not have active bleeding and is stable enough to go to radiology, chest CT may assist finding the etiology of hemoptysis. Bronchiectasis, lung abscess, pulmonary artery aneurysm, pulmonary embolism, and mass lesions are all abnormalities that can be identified by chest CT.