Introduction: Assessment of nitric oxide (NO) concentration in exhaled air is broadly used to monitor the airway inflammation in asthma. High levels of NO are also observed in paranasal sinuses and gastrointestinal tract (GT). Properly functioning esopahageal sphincters are responsible for maintaining NO in the GT. So far, it has been unknown how much the GT disorders and especially the disorder of esophageal motility can affect FeNO (fractional exhaled nitric oxide) measurements. The aim of the study was to assess whether the gastroesophageal reflux disease has any impact on the level of NO in the exhaled air in patients who do not suffer from any airway diseases. Material and methods: Gastroscopy with biopsy was performed in 51 patients, in whom asthma, allergic rhinitis and atopy were excluded. In 13 of them, no esophageal pathology was found and they were considered as the control group. In the remaining 38 patients, the severity of esophagitis was evaluated according to the Los Angeles classification. Results: The concentration of NO in the exhaled air of patients with endoscopic gastroesophageal changes did not differ significantly from NO concentration in patients without inflammatory changes in the stomach and esophagus (p = 0.68). The presence of the hiatal hernia did not affect the FeNO concentration either (p = 0.67). There was no statistically significant correlation between the NO level and infection with Helicobacter pylori (p = 0.18). Conclusions: The gastroesophageal pathologies did not affect the NO concentration in exhaled air significantly.