Background: Rural children are at a particular high risk for obesity. Given the importance of exercise in obesity and chronic disease prevention, this study evaluated the level and relationship between physical activity and fitness in a sample of rural third graders. The second purpose of the study was to determine potential differences in physical activity and fitness level by weight status in this sample. Methods: Twelve schools participating in a multidisciplinary research project were randomly selected for the study. Body mass index-for-age percentile, the modified Self-administered Physical Activity Checklist, and the FITNESSGRAM battery tests were utilized to determine children's weight status, physical activity, and fitness level, respectively. Results: Thirty-eight percent of the 237 participating children (9.2 [plus or minus] 0.4 years) were overweight or obese. Nearly 15% were extremely obese. Children spent 91.8 [plus or minus] 83.8 and 32.2 [plus or minus] 47.7 minutes in moderate- and vigorous-intensity activities. Obese children spent less time in moderate-intensity activity (p less than 0.01) and combined moderate- and vigorous-intensity activity more than other children (p less than 0.05). Forty-three percent of all children failed to meet the fitness standard for muscular strength and 36% failed to meet it for flexibility. Conclusions: Rural children in this sample had higher rates of obesity compared to the national average; they had poor fitness and 30% failed to meet the minimum physical activity recommendations on the previous day. Future interventions should focus on increasing physical activity, especially of moderate-intensity, and improving physical fitness in order to reduce obesity and decrease the risk of future chronic diseases in this high-risk population. (Contains 2 tables.)