In this study, we examined the function of depression, anxiety, and aggression as dysfunctional schemas in the relationship between stress and internet addiction. A total of 464 elementary school students participated in this study. To analyze the data, hierarchical regression analysis was conducted. The results indicated that only aggression fully mediated the relationship between stress and internet addiction. On the other hand, other dysfunctional schemas such as depression and anxiety did not mediate the relationship bewteen stress and internet addiction. In addition, three dysfunctional schemas such as depression, anxiety, and aggression did not moderate the relationship between stress and internet addictions. As a result, decreasing aggression is important to reduce internet addiction for students who have high stress. Finally, the implications of the findings were discussed in the context of stress, dysfunctional schemas, and internet addiction.