The aim of this study is to investigate the effect of relational-interdependent self-construal on cyberbullying and the effect of cyberbullying on psychological disharmony. Participants were 258 high school students. In this study, the Relational-Interdependent Self-Construal Scale, the Revised Cyberbullying Inventory, and the Depression, Anxiety, Stress Scale were used. In correlational analysis, cyberbullying and cyber victimization were found negatively related to relational-interdependent self-construal. On the other hand, cyberbullying and cyber victimization were found positively related to depression, anxiety, and stress. The goodness of fit indices indicated that the model was fit. According to structural equation modelling (SEM) results, relational-interdependent self-construal predicted negatively cyberbullying, and cyberbullying predicted psychological disharmony in a positive way.