Background & objectives: Measurement of physical activity (PA) is always a challenge. Utilizing self reporting tools has been rather controversial while talking on children physical activity assessment. Present study assesses children’s PA using a self- report checklist and compares it with parent-report method. Methods: In this study that evaluates PA of children using a self-report tool and compares it with the parent-report one, the self-report tool was utilized on 300 grade 5 and 6 students that were selected through multi-stage sampling method. The compiled data were compared with those of parent-reported results. Results: The mean Vigorous physical activity (VPA), Moderate Physical Activity (MPA), and Energy Consumption (Metabolic Equivalent MET) indices in boys were significantly higher than the girls (t-test, p=0.001). Despite the significant difference in MET estimation between the results of self- and parent-reports, there was a significant correlation with a coefficient of 0.9 between the results obtained from two tools. Conclusion: Differences in mean MET estimations between self- and parent-reports are due to the differences in their utilized time periods. This was proved through significant correlation observed between the two estimations. Therefore, self-report checklist can be used as a valid tool for assessment children's physical activity. Yet, comparing the self-report checklist outcomes with the ones from other physical activity assessment techniques is recommended.