Ultrastructure of the cilia of the bronchial epithelium was studied in 26 patients with Zivert-Kartagener syndrome, 12 patients with bronchiectasis and 10 patients with cystic lung hypoplasia. All changes of the cytolemma and cytoskeleton are found to be of a combined type. The degree of the bronchial inflammation was of the decisive influence on the state of the ciliary cells. Common features of the ultrastructural alterations are noted in the groups of patients compared. Ultrastructural defects characteristic for the patients with the Zivert-Kartagener triad were not found. It is concluded that all the ultrastructural defects of the ciliary epithelium were of the acquired character.