Background. Patients with cystic fibrosis (CF) fall into the risk group of breathing passages infection as a result of clinical features of the disease. During the period of COVID-19 pandemic,the necessity of understanding how infection affects the course of the main disease has appeared, taking into account that viability of patients is essentially determined by the degree of lung lesion. Early diagnostics and complex therapy of coronavirus infection increase the lifespan of CF patients and improve quality of life. X-ray examinations play the leading role in solving this problem. Purpose – to establish risk factors of the main pathological process aggravation by determining diagnostic significance of roentgen sings of lung lesion in COVID-19 in CF adult patients. Materials and methods. Theanalysis of radiography and computed tomography results of 11 adult patients with CF of moderate and severe degree who were also diagnosed with coronavirus infection. Results. The main X-ray symptoms in observed patients with CF with confirmed diagnosis of coronavirus infection was pneumonic infiltration of different degrees in the setting of diffuse changes of lung pattern and features of pulmonary emphysema. Besides symptoms of the main disease, computed tomography allowed us to find the signs, which we consider to be the signs of pneumonia caused by COVID-19 infection – induration of lung tissue in the form of ground-glass opacity, presence of ground-glass areas of different shapes with reticular changes and consolidation of lung tissue, bilateral localization of pathological changes, predominantly in basal and subpleural areas. Conclusions. Lung lesion conditioned by COVID-19 in radiography of CF patients may be disguised by the features of the main disease manifestations. Therefore, any X-ray evidence of inflammatory lung changes in CF patients during the epidemic period must be regarded as COVID-19 suspected, and polymerase chain reaction and computed tomography must be performed.