The purpose of the study was to determine the frequency rate of Pseudomonas aeruginosa infection among children with cystic fibrosis (CF) in Dnipro region and to provide microbiological characteristics of the obtained isolates. The study was conducting from January 2019 to December 2020. Children with genetically confirmed CF diagnosis were enrolled. The main research method was bacteriological with identification of microorganisms by biochemical properties; antimicrobial susceptibility was determined by disk-diffusion method. Biological material: mucus from a deep smear from the posterior pharyngeal wall, sputum and tracheobronchial lavage waters. The Leeds criteria were used to define persons with chronic infection. The study involved 21 children. We collected 183 respiratory samples with 49 isolates of P. aeruginosa. The most important co-existing pathogens were Staphylococcus aureus, Aspergillus spp. and Candida spp. In our study, P. aeruginosa was associated with Aspergillus spp. (χ2=20.952; df=1; p˂0.001). Mucoid isolates were found in 24.49% of cases. P. aeruginosa showed variable sensitivity to different groups of antimicrobial agents, but the highest resistance was to penicillins. Mucoid P. aeruginosa was more resistant to penicillins (p˂0.001) and cephalosporins (p=0.036). Infection P. aeruginosa is frequent among children with CF; there were three children with chronic bronchopulmonary infection P. aeruginosa in Dnipro region in the end of 2020. The likelihood of Aspergillus spp. infection was higher in the case of current P. aeruginosa infection. P. aeruginosa showed variable susceptibility to different groups of antimicrobial agents, but mucoid isolates were more resistant.