Aim. To assess the state of membranes in nasal epithelial cells obtained from the patients with chronic rhinosinusitis with nasal polyps (CRSwNP) with the help of the fluorescent probe 2-(2ʹ-ОН-phenyl)-5-phenyl-1,3-oxazole. Methods. The state of membrane phospholipid bilayer in suspensions of nasal epithelial cells isolated from ten patients with CRSwNP was evaluated using the fluorescent probe 2-(2ʹ-ОН-phenyl)-5-phenyl-1,3-oxazole that reacts on the physico-chemical properties of its microenvironment. Changes in fluorescence spectra were determined using a Thermo Scientific Lumina fluorescence spectrometer (Thermo Fisher Scientific) 1 hour after the addition of the probe to nasal epithelial cell suspensions. Results. CRSwNP was found to be associated with a higher rate of nasal epithelial cell membrane hydration in the region of phospholipid glycerol moiety, carbonyl groups and aliphatic chains of fatty acids attached to the carbonyl groups. Conclusion. Our findings suggest that CRSwNP is accompanied by the elevated hydration rate of the most polar region, namely polar heads of phospholipids of nasal epithelial cell membranes
