The purpose of this study is to determine the overweight and obesity prevalence among students studying in primary school by ages and to reveal the relation with physical activity. 1946 students aged between 7 and 11 and receiving primary education in a district of Manisa province have participated in this study. There are 885 female students and 1061 male students. Height measurements, body composition measurements, vertical jump test and 30mt tests of the participants were performed respectively. SPSS 22 program was used for statistical analysis. Frequency distributions and percentage values were presented in statistical notations. Pearson correlation analysis was performed in data analysis. In conclusion, it is observed that 12% of female students are overweight, 9.5% are obese and 21.5% are both overweight and obese. 8.8% of male students are overweight, 11.3% are obese and 20.1% are both overweight and obese. There is also a statistically correlation between obesity and age and parameters of physical fitness. In order to reduce the prevalence of overweight and obesity in children, school and community-based programs must be planned to encourage children to do physical activity and exercise and to prefer low calorie intake. The content and importance of these programs should be made applicable by parents and local governments.