Congenital abnormalities of the bronchi have been classically described with chest X-rays, conventional tomography, bronchography, CT and MR imaging. Recently, the capacity of spiral CT to explore a complete volume with no gap and excellent multiplanar reformations has been emphasized. The contribution of this technique to the analysis of congenital anomalies of tracheobronchial branching patterns encountered in adult patients is illustrated. Agenesis, aplasia, and hypoplasia are discussed, followed by bronchial atresia and abnormalities of bronchial divisions. In most cases spiral CT permits a full and correct evaluation of the malformation as well as its associated anomalies. It appears therefore to be the preferable technique for studying such anomalies of the tracheobronchial tree. Moreover, knowledge of CT aspects of the main congenital bronchial abnormalities along with complete visualization of the tracheobronchial tree will probably lead to detection of more incidental anomalies.