A prospective evaluation of segmental and subsegmental bronchi of 104 right and 109 left lungs was made from oblique CT scans of patients with normal airways. The frequency of identification of each of these bronchi was compared with the results of a similar retrospective analysis of 107 right and 113 left lungs, studied with standard vertical CT slices. The percent visualization of all bronchial ramifications is tabulated, allowing us to state that the 20 degrees cranially oblique slice considerably improves CT analysis of the bronchial tree. Several potential uses of oblique CT are discussed and applied to bronchial disease evaluation.