BACKGROUND: The present study was undertaken to know health-related lifestyles of Republic of Korea Air Force (ROKAF) pilots and to investigate prevalence of obesity of them.METHODS: 1284 KAF pilots were checked their height, weight, and body composition (% body fat). We also tried questionnaires on their health-related lifestyles which included the effort to be healthy, whether they know weight training is beneficial to G-tolerance, exercise habit and smoking history. RESULTS: Pilots' attitude for health promotion was relatively passive. Many of them know that weight training is good for their G-tolerance, but only 8.1% of the pilots carried out that training. They engaged much more in aerobic training, and also fighter pilots are less participated in weight training than transport pilots. The prevalence of obesity (29.4%) determined by bioelectrical impedance analysis was much higher than that assessed on the basis of height and weight (BMI, body mass index). It is suggested that many pilots who were normal in BMI have abdominal or visceral obesity. CONCLUSION: The health promotion program and physical conditioning program related to increasing G tolerance of KAF pilots flying high-performance aircraft are very important. These programs must be organized and progressed with flight surgeon and Aeromedical center in Chung-ju as leaders.