Despite the low prevalence of cystic fibrosis (CF), the costs of treating this disease are significant for the healthcare system. The aim of this economic study was to assess the total cost of drugs per year for children with CF, depending on age and course of the disease.Methods. For this pharmacoeconomic analysis, groups of “hypothetical” patients were formed according to the characteristics of the course of CF, taking into account the required volume of basic CF therapy, antibiotic therapy, and complications.Results. The cost of basic treatment for CF patients of different ages and disease progression in the hypothetical patient models can vary greatly. The cost of CF therapy increases significantly with age and Pseudomonas aeruginosa respiratory infection, especially in the patients with chronic infection, concomitant polyposis sinusitis, and low nutritional status.Conclusion. Patients with CF require regular follow-up with control of the microflora of the respiratory tract and effective eradication therapy for P. aeruginosa and other pathogenic microorganisms. Reducing infection rates and the severity of the disease can lead to significant cost savings.