Cystic fibrosis (CF) is a multisystemic autosomal recessive disease caused by a defect in the expression of CFTR protein, i.e. chloride channel present in the apical membrane of respiratory, digestive, reproductive and sweat glands epithelium. It primarily occurs in the Caucasians, while being considerably or excep tionally rare in persons of other races. Absence, deficit or structural and functional abnormalities of CFTR protein lead to mucosal hyperconcentration in the respiratory, digestive and reproductive systems and malabsorption of chloride and sodium in the sweat glands. Thus, the clinical features of patients' with CF are predominated by respiratory, digestive and reproductive disorders, as well as the tendency to dehydration in the condition of increased sweating. Beside genotype variations, the degree of disease manifestation is also essentially influenced by various exogenous factors, such as the frequency and severity of respiratory infections, the level of aero-pollution, quality of immunoprophylaxis, patients' nutritional condition and other. Chloride concentration of over 60 mmol/L in sweat, a high level of immunoreactive chymotrypsinogen in blood and the verification of homozygous mutation of CFTR gene are the basic methods in the diagnostics of the disease. CF belongs to the group of severe and complex chronic diseases, and therefore requires multidisciplinary therapeutic approach. Owing to the improvement of healthcare provision, most patients with CF now survive into adulthood. In addition, their quality of life is also considerably improved.