Computed tomography (CT) was performed on six patients with bronchiectasis. In two cases of advanced cystic bronchiectasis, the diagnosis was apparent on plain chest roentgenograms. In four cases, bronciectasis was initially diagnosed by CT and later confirmed by bronchography. The CT signs of bronchiectasis include air--fluid levels in distended bronchi, a linear array or cluster of cysts, dilated bronchi in the periphery of the lung, and bronchial wall thickening due to peribronchial fibrosis. Distended bronchi must be distinguished from emphysematous blebs, which generally have no definable wall thickness and no accompanying vessels. It is concluded that CT should have a role in establishing the presence and anatomic extent of bronchiectasis.