Background: To improve support and justi?cation for health promotion efforts in schools, it is helpful to understand how students' health behaviors affect academic performance. Methods: Fifth-grade students completed an online school-administered health survey with questions regarding their eating behavior, physical activity, academic performance, and sleep patterns. Differences in health behaviors were examined by sex, self-reported weight status, and suf?cient (greater than or equal to 9 hours) versus insuf?cient sleep. Logistic regression was used to determine the relationship between academic performance and the health behaviors. Results: One third of the sample did not get the recommended amount of physical activity and more than half of the students watched television greater than or equal to 2 hours/day. Self-reported overweight status was related to lower self-reported academic performance, fewer lunch and breakfast occasions, less physical activity, not meeting the recommendations for vegetable and soda consumption as well as hours of television watching. Suf?cient sleep (greater than or equal to 9 hours/night) was associated with better grades, meeting the recommended hours of daily television watching and video game playing, being more physically active and increased breakfast and lunch frequency. Percentage of serving free/reduced lunch, soda consumption, breakfast frequency, amount of physical activity, and television watching were associated with academic performance. Conclusion: More positive health behaviors generally were associated with better academic performance. Promoting healthy behaviors in schools might improve not only students' health academic performance as well. (Contains 4 tables.)