Despite limitations, high-resolution computed tomography (HRCT) continues to be the gold standard for establishing the anatomic extent and severity of bronchiectasis. HRCT allows insight into the physiologic consequences of bronchiectasis. Recent reports show that there is good correlation between measurements of the density of airway walls and airway obstruction in patients with chronic obstructive pulmonary disease. Measuring peak airway wall density may prove of value for assessing the severity of bronchiectasis as well as potentially serving as a biomarker for measuring response to therapy. The full potential of computed tomography for evaluating airways disease has yet to be fully explored.