It is known that high-altitude trips cause nasal congestion, impaired nasal mucociliary transport rate, and increased nasal resistance, due to decreased partial oxygen pressure and dry air. It is also known that olfactory perception is affected by barometric pressure and humidity. The aim of the present study was to investigate whether olfactory function changes in relation to high altitude in a natural setting. The present study included 41 volunteers with no history of chronic rhinosinusitis or nasal polyposis. The study group consisted of 31 men (76 %) and 10 women (24 %); the mean age of the study population was 38 ± 10 years. Olfactory testing was conducted using "Sniffin' Sticks" at a high altitude (2,200 ms) and at sea level. Odor test scores for threshold and identification were significantly better at sea level than at high altitude (p < 0.001). The major finding of this investigation was that olfactory functions are decreased at high altitudes.