Cystic fibrosis is genetic multisystem disorder with a predominant lesion of the respiratory tract. The duration and quality of life of these patients depends on the state of respiratory function. Progressive lung dysfunction is still the leading cause of mortality patients with cystic fibrosis. End-stage lung diseases in patients with cystic fibrosis, lung transplantation is a viable method of treatment. It has the ability to prolong life of these patients. Survival in cystic fibrosis has steadily increased medical treatment and post-transplant. Chronic rhinosinusitis (with nasal polys and without) impacts almost all cystic fibrosis patients, leading to significant reductions in quality of life. Chronic rhinosinusitis with nasal polyps is prevalent in the cystic fibrosis patients, and it is often a recalcitrant infection with multidrug resistant organisms. Medical therapies such as nasal irrigations, nasal steroids, and antibiotics are critical for managing symptoms, but functional endoscopic sinus surgery is necessary for refractory cases. The unified airway hypothesis suggests that sanitation bacterial infection in the upper airway can also decrease bacterial burden in the lungs. The article presents a clinical case of successful endoscopic sinus surgery in a 15-year-old patient with chronic rhinosinusitis with nasal polyps and cystic fibrosis after lung transplantation. The intervention was performed under General anesthesia and controlled hypotension. Bilateral antrostomy, ethmoidectomy and Draf IIb frontal sinusotomy were performed by endoscopic endonasal approach. There were no intra - and post-operative rhinosurgical or lung complications. The follow-up period was 18 months. At present, there is no relapse of chronic polypous rhinosinusitis, and there are no indications for revision intervention.