PURPOSE: Despite the high prevalence of headaches in students, their lifestyles have not been well examined. We examined correlation between lifestyle and headache in Korean students. METHODS: We conducted a cross-sectional, school-based study from a randomized and proportional sample of 5,360 male and female students. The questionnaires include demographic data, lifestyle, in addition to specific questions about headache according to International Classification of Headache Disorder II (ICHD-II) criteria. Valid questionnaires were returned by 94.1% (5,039, boys 2,405, girls 2,634) of the sample. Modified criteria changed the item 'duration' in migraine (>1 hour instead of 4 hours). We analyzed the data in terms of exercise, regular eating, sleep time, fluid intake, and caffeine intake. RESULTS: Students on regular exercise have less headache (P=0.03). Students who eat regularly have less recurrent headache (P<0.0001, odds ratio=0.5). Students sleep more have less headache (P<0.0001). Students take more fluid have less headache (P=0.0002). Students take more caffeine have more headache (P=0.0001). CONCLUSION: There seem to be a significant relationship between life style and headache in school children in South Korea. We suggest that changing the lifestyles or habits should be considered to manage and prevent headaches in school children.