Hemoptysis is the expectoration of blood from the lung parenchyma or airways. The initial step in the evaluation is determining the origin of bleeding. Pseudohemoptysis is identified through the history and physical examination. In adults, acute respiratory tract infections (e.g., bronchitis, pneumonia), bronchiectasis, asthma, chronic obstructive pulmonary disease, and malignancy are the most common causes. Tuberculosis is a major cause of hemoptysis in endemic regions of the world. Although tuberculosis rates are low in the United States, they are increased in persons who are homeless or who were born in other countries; consideration for testing should be made on an individual basis. Hemodynamic instability, abnormal gas exchange, cardiopulmonary comorbidities, and lesions at high risk of massive bleeding warrant inpatient evaluation. Chest radiography is recommended as the initial diagnostic test for hemodynamically stable patients with hemoptysis. Further evaluation with computed tomography with or without bronchoscopy is recommended in patients with massive hemoptysis, those with abnormal radiographic findings, and those with risk factors for malignancy despite normal radiographic findings.