The world is competitive in every possible way, especially in the education sector, so university students tend to seek success in their academic field and try to get attention in their social circle regardless of any cost or effort involved. Consequently, this leads to the narcissistic personality among the university population. This study aimed to investigate the mediating role of narcissism in the relationship between self-esteem and aggression among university students in Sagaing. The sample comprised 1058 undergraduate students distributed as 519 females and 539 males from undergraduate classes. Rosenberg’s self-esteem scale by Rosenberg (1965), the Narcissistic Personality Inventory by Raskin & Terry (1988) and the aggression questionnaire by Buss & Warren (2000) were used. The result of the mediation analysis revealed that self-esteem has a direct negative effect on aggression and also an indirect positive effect on aggression through the mediation effect of narcissism. This clearly indicates the suppressor effect, competitive mediation, since the positive relationship between self-esteem and aggression is reversed when narcissism is mediated as a suppressor variable. As this suppressor effect is enticing for the researchers in the academic field of psychology, further studies should explore the moderating factors in the relationship between self-esteem, narcissism and aggression. It is anticipated that the current study will provide the basic information that can contribute to the development of the prevention programme for narcissism and aggression in the higher education sectors with a strong emphasis on the self-esteem of university students.
