Hemoptysis is defined as the expectoration of blood originating from the tracheobronchial tree or pulmonary parenchyma, ranging from 100 mL to 1 L in volume over a 24-hour period. This article reviews the literature on the indications and usefulness of radiologic studies for the evaluation of hemoptysis. The following recommendations are the result of evidence-based consensus by the American College of Radiology Appropriateness Criteria Expert Panel on Thoracic Radiology: (1) Initial evaluation of patients with hemoptysis should include a chest radiograph; (2) Patients at high risk for malignancy (>40 y old, >40 pack-year smoking history) with negative chest radiograph, computed tomography (CT) scan, and bronchoscopy can be followed with observation for the following 3 years. Radiography and CT are recommended imaging modalities for follow-up. Bronchoscopy may complement imaging during the period of observation; (3) In patients who are at high risk for malignancy and have suspicious chest radiograph findings, CT is suggested for initial evaluation; CT should also be considered in patients who are active or exsmokers, despite a negative chest radiograph; and (4) Massive hemoptysis can be effectively treated with either surgery or percutaneous embolization. Contrast-enhanced multidetector CT before embolization or surgery can define the source of hemoptysis as bronchial systemic, nonbronchial systemic, and/or pulmonary arterial. Percutaneous embolization may be used initially to halt the hemorrhage before definitive surgery.