Background: A pilot’s hypoxia which may lead to dysfunction in some vital and sensitive organs can be detected and its prevention may greatly reduce the rate of aviation accidents. Therefore, this study aimed to investigate the prevalence of hypoxia using a pulse oximeter among pilots in an altitude chamber (hypobaric chamber).

Materials and methods: In a cross-sectional study on 80 pilots referred to IR.AF aviation physiology center, the level of blood oxygen saturation (SpO₂) was measured before and during the experience of hypoxia in altitude chamber (25,000 feet). SPSS software was used for statistical analysis.

Results: The mean SpO₂ level during experience of hypoxia was about 81.5% and most of aviators experienced the symptoms of hypoxia in SpO₂ of 89-80%. In three cases (3.7%) symptoms occurred when SpO₂ level was in critical range (69-60%).

Conclusion: Our results showed that symptoms of hypoxia in some pilots occurred in very low levels of SpO₂ and this can lead to sudden loss of consciousness without any physiological notice. Pulse oximetry technology could be of great importance to pilots in early detection of hypoxia. Particularly aviation pulse oximeters may expressively prevent aviation accidents related to pilot’s hypoxia by early detection and timely warning to pilots during in-flight hypoxia.