Objective: This study investigates the impact of early morning physical exercises on reduction of aggression in children with mental retardation. Method: 14 male students with educable mental retardation ageing 9 to 17 year old, with an available method, from one school were selected, and randomly assigned to experimental and control groups. The research was conducted according to the semi -experimental method using pre-test, post-test design and follow-up for the control group. Results: The result of the statistical analysis through repeated measure design revealed a significant difference between the two groups. After a one-month follow-up, the results were stable and the finding showed that early morning exercises could significantly reduce the amount of aggression in the students with educable mental retardation. Conclusion: This research shows that morning physical exercises can be considered as a useful way to be used to help children with mental retardation.