Background: Obesity has become a national epidemic among youth. Declining physical activity and poor nutrition contribute to this epidemic. The purpose of this study was to obtain data on middle school students' physical activity and nutrition knowledge and practices. Methods: The Youth Physical Activity and Nutrition Survey was developed and distributed to a probability sample of Florida public middle schools (n = 73) in spring 2003, producing data from 4452 students in grades 6-8. Results: Results showed that less than one fourth of youth met expert recommendations for daily fruit and vegetable intake and less than one fifth identified the daily fruit and vegetable serving recommendation. Less than half of students reported eating breakfast daily. More non-Hispanic black youth reported not engaging in vigorous or moderate physical activity during the previous 7 days, and more girls and Hispanic youth reported not attending any physical education classes during the average school week. Conclusion: These findings demonstrate that dietary and physical activity behaviors and knowledge among these middle school youth are setting the stage for the obesity epidemic to continue. (Contains 4 tables.)