Transcatheter therapy is an effective technique in the treatment of vascular abnormalities in the chest. Pulmonary arteriovenous malformations, associated with the clinical sequellae of dyspnea, stroke, brain abscess, and hemoptysis, can be treated by transcatheter embolization with metallic coils or occlusion balloons. The results of treatment are excellent, with improvement seen in symptoms and physiologic parameters. The bronchial arteries and systemic nonbronchial collateral arteries supplying the tracheobronchial tree are most frequently involved in massive hemoptysis, a serious disorder with associated high rates of morbidity and mortality. Transcatheter embolization of these arteries is both safe and effective, requiring a thorough understanding of the arterial anatomy and technique of embolization.