Cilia (cilia) are organelles that are characteristic exclusively for eukaryotes and are found in protozoa, on somatic and germ cells of multicellular, as well as gametes of many plants. In humans, two main types of cilia are distinguished: motile and sensory; also in embryogenesis, it is customary to isolate special nodular cilia necessary for the normal course of gastrulation and possibly subsequent histo- and organogenesis. Motile cilia provide the movement of the liquid medium relative to the cell in the respiratory tract, the ventricular system of the brain and the fallopian tubes, or the movement of the cell itself in the case of sperm. The main function of sensory cilia is the perception of changes in the external environment and the signal molecules inside it and their conversion into intracellular signals that regulate proliferation, differentiation, and programmed cell death. Ciliopathies, a group of pathological conditions associated with impaired development, structure, and functioning of cilia, are of clinical interest. The most studied ciliopathies include polycystic kidney disease, nephronophysis, Barde-Beadle, Joubert, Mekel, Kartagener, Karoli etc. Clinical nephronophthisis and morphological analysis of the case of Caroli, syndrome is given.