Objectives: Cigarette smoking affects performance and attention, but its relationship is unclear. Aviators require sustained, focused attention to maintain aviation safety, but they are frequently exposed to high-altitude environments. In this study, we intended to investigate whether pre-flight cigarette smoking would affect the attention of military aviators at a simulated altitude of 18,000 feet created by a hypobaric chamber. Methods: We evaluated 96 (72 smokers and 24 non-smokers) aviators with the visual search and the incompatibility task. All participants took part in two tasks in a hypobaric chamber at ground level. We randomly chose 48 participants in the smoking group to receive a piece of cigarette with a nicotine dose of 1.0 mg; the other participants in the smoking group (n = 24) received a piece of cigarette with a nicotine dose of 0.1 mg (smoker group 2). After we gave the smoking participants a piece of cigarette, the smokers who received the 1.0 mg nicotine dose were equally divided into two groups (smoker groups 1 and 3; n = 24 each). All aviators except those in smoker group 3 (at ground level for the whole procedure) were subjected to altitude of 18,000 feet. Participants undertook the two tasks again. Results: In smokers, cigarette smoking was found to have a positive effect on reaction time in both visual search and incompatibility tasks, regardless of altitude. The trend was not clear about attitude and attention since no difference was found among smoker group 1 and 3. Conclusion: Cigarette smoking facilitates attention during the visual search and incompatibility tasks in smokers at 18,000 feet of altitude.