Chest X-ray remains important to depict lesions located in hilar and pulmonary vessels, despite the variable accuracy of the technique. Whereas large hilar masses are easily identified, small lesions may be more difficult to detect. Knowledge and careful evaluation of hilar anatomy, however, yield significant information. There is a large variety of congenital and acquired diseases affecting the pulmonary vessels, which can be detected on chest X-ray. When the presence of a pulmonary vascular abnormality is suspected, computed tomography is invaluable because it allow analysis of the pulmonary vessels, the lung parenchyma, the heart, the pleura, the mediastinum, and the thoracic wall in a single examination.