Aim. To investigate the clinical features of cystic fibrosis (CF) in adult patients with carbohydrate metabolic disturbances (CMD). Material and methods. CF was diagnosed on the basis of its clinical picture and a positive sweat test, and/or genetic study. Clinical, anthropometric, functional, microbiological data were compared with the results of imaging diagnosis in CF patients with and without CMD. Results. The data of 350 patients were retrospectively analyzed. An oral glucose tolerance test was randomly performed in 154 CF patients without CMD. There was normal carbohydrate metabolism in 92 (59.7%) patients with CF, impaired glucose tolerance (IGT) in 44 (28.6%), CF-dependent diabetes mellitus (CFDDM) in 18 (11.7%). The latter had been previously diagnosed in 37 (10.6%) other patients with CF. Three groups of patients were formed: 1) 92 patients without CMD; 2) 44 with IGT, and 3) 55 with CFDDM. The patients with CFDDM had lower stature, weight, and lung function, significantly more common bronchiectases, a lower Staphylococcus aureus colonization with a tendency toward a higher Burkholderia cepacia colonization than those without CMD. As compared with the patients without CMD, those with this disorder were found to have a high rate of severe mutations; mild mutations were absent in the patients with CFDDM. Conclusion. CMD in CF is characterized by its high rates and latent course. The patients with CMD have retarded physical development, more pronounced morphofunctional disorders in the bronchopulmonary system, lower lung functional parameters, and more aggressive sputum microbial composition.