Objective <p>Since children left behind in rural areas are more prone to aggressive behavior due to incomplete families or inappropriate parenting styles, it is essential to identify influencing factors and potential mechanisms to mitigate their aggression. This study aims to examine the relationship between physical exercise and aggressive behavior among rural left-behind children in China and the mediating effects of psychological capital and self‑control.</p> Methods <p>Participants consisted of 453 rural left-behind children (Mage = 12.58, SD = 1.41; boys = 231, girls = 222) from two rural primary schools and two rural junior high schools in a city in central China. These rural left-behind children completed a questionnaire measuring physical exercise, psychological capital, self-control, and aggressive behavior. Descriptive analysis, correlation analysis, and mediation analysis were conducted using SPSS software and the Process plug-in.</p> Results <p>The results showed that (1) physical exercise, psychological capital, and self-control were all significantly positively correlated with each other, and they were all significantly negatively correlated with aggressive behavior. (2) psychological capital and self-control partially serve as both independent and chain mediators between physical exercise and aggressive behavior.</p> Conclusion <p>This study provides further insight into the underlying mechanisms linking physical exercise and aggressive behavior in rural left-behind children. Physical exercise not only has a direct negative effect on aggressive behavior but also indirectly predicts aggressive behavior through its impact on psychological capital and self-control. This mediating effect model provided a valuable insight for improving their physical exercise and preventing aggressive behavior.</p>