The aim of this study is to examine the effect of internet parental style on cyberbullying and cyber victimization of high school students and the relationship between big five personality traits, cyber bullying and cyber victimization. In accordance with this aim, 467 students studying in various high schools in Sakarya in autumn semester of 2014-2015 education year were selected as sample. 244 (52.1%) of the students are males, 223 (47.8%) of them are females. Cyber Bully/Victim Questionnaire, Internet Parental Style Scale and Big Five Personality Inventory were used as data collecting instruments in the research. In the research cyber bullying and cyber victimization were selected as dependent variables, big five personality traits (extraversion, agreeableness, conscientiousness, neuroticism and openness), internet parental style (parental control and parental warmth), gender and age variables were considered as predictive variables. To examining these relationships regression analysis was conducted. As a result of regression analysis agreeableness, parental control and gender were found as the predictors of cyber bullying. Second result of regression analysis showed that, gender and parental control were found as predictors of cyber victimization. The findings were discussed in the light of related literature.