Physical performance and work capacity is negatively influenced by excess body fat. The study was conducted to find out the relationship between percentage body fat (PBF) with performance of strength endurance and cardio vascular endurance. A total of 210 school boys of 10 to 15 years of age were randomly selected as subjects for this study. PBF was calculated by anthropometric equation developed by Lohman et al. and strength endurance and cardio vascular endurance were measured with standard tests. Mean and SD were computed for each parameter as descriptive statistics and coefficient of correlation (r) was computed by Pearson’s Product Moment method using standard statistical software. Results revealed that PBF had negative correlation with strength-endurance and cardio- vascular endurance. These relations were found significant for both strength-endurance and cardio- vascular endurance in this study. From findings it might be concluded that the 10 to 14 years school going boys who have more PBF, are lesser performer in respect of strength-endurance and cardio vascular endurance.