Dynamic computed tomography (CT) was performed in nine patients with enlarged bronchial arteries documented by arteriography. Plain and contrast-material-enhanced CT scans of two more patients with prominent bronchial arteries were retrospectively reviewed. The study was conducted to determine visibility of the bronchial artery with CT and to depict the anatomic relationship of its mediastinal portion to surrounding structures. The mediastinal portion of the bronchial artery was successfully outlined as nodular or linear densities on all dynamic CT scans. The right bronchial artery was confirmed to arise from the medial wall of the thoracic aorta, whereas the left arises from the anterior wall. Because of its retroesophageal location, the enlarged right bronchial artery can compress the posterior wall of the esophagus. It is postulated that the left bronchial artery occasionally traverses the aorticopulmonary window, recognized as nodular or linear densities below the aortic arch on CT scans.