BACKGROUND: Immunosuppressive treatments are increasingly prescribed in a variety of diseases. This issue concerns airmen.METHODS: To assess the problem, we conducted an observational retrospective study in the aircrew population examined in 2014 at the Aeromedical Center of Percy Military Hospital.RESULTS: Airmen treated with immunosuppressive drugs accounted for 0.5% of the total population (N = 13,326). Rheumatic and digestive diseases were the main etiologies, respectively 43% and 35% of cases. One-third of airmen took such medications during at least 3 yr and three-quarters of airmen were declared fit to fly, with some limitations.DISCUSSION: Due to their working conditions, airmen are exposed to a real infectious risk, which is, however, difficult to evaluate. The risk is obviously increased by immunosuppressive drugs and may affect flight safety. Aeromedical evaluation should consider this problem. Vaccination plays a central role in the prevention of infectious risk. Based on French recommendations, we propose a vaccination schedule for these particular patients.Guiu G, Monin J, Hamm-Hornez A-P, Manen O, Perrier E. Epidemiology of airmen treated with immunosuppressive drugs and vaccination concerns. Aerosp Med Hum Perform. 2018; 89(4):377–382.