The objective of the present study was to measure pH values and mucociliary clearance (MCC) in the patients presenting with chronic rhinitis and pyo- inflammatory diseases o f paranasal sinuses. A total of 100 subjects included into the study were allocated to three groups. Group 1 was comprised of 20 healthy volunteers, group 2 consisted of 40 patients with chronic rhinitis, and group 3 included 40 patients presenting with pyo- inflammatory diseases o f paranasal sinuses (PNS). The study showed that chronic rhinitis was associated with the shift of mucosal pH values towards the alkaline side (pH = 7.5±0.5) accompanied by suppression of mucociliary transport in the intranasal mucous membrane. In the patients with acute and chronic sinusitis, the acid-base equilibrium was shifted towards higher acidity (pH = 6.8±0.13). The results of the study indicate that the inflammatory process exerts negative effect on the functional state of the intranasal mucous membrane accompanied by the shift of the acid-base equilibrium and the suppression of mucociliary transport.