Although hemoptysis is often self-limited and benign in origin, it can be an indicator of serious disease including bronchiectasis, granulomatous infection, and malignancy. Hemoptysis severity can be graded on the basis of the quantity of expectorated blood: <30 mL of hemoptysis as minor, 30 to 300 mL as moderate to severe (major), and >300 to 400 mL in 24 hours as massive. Among patients with hemoptysis, chest radiographs are often abnormal and can guide evaluation. The overall risk for malignancy in patients with normal radiographs is low but may be as much as 5% to 10% in patients with >30 mL of hemoptysis and those who are above 40 years of age and have significant smoking history. A combination of negative computed tomography and bronchoscopy results predicts a very low likelihood of lung malignancy diagnosis over medium-term follow-up (2 to 3 y). Bronchial and nonbronchial systemic arteries are much more frequent sources of hemoptysis than pulmonary arteries. Major or massive hemoptysis can usually be stopped acutely by bronchial arterial embolization. Recurrences, however, are common and often require repeat embolization. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.