Cyberbullying awareness of parents is significant to reduce exposure to cyberbullying. However, it is noteworthy that there are limited studies on the factors affecting parents' knowledge and competencies about cyberbullying and the change of these factors according to the education level of the child. This study aims to determine the relationships among cyberbullying knowledge and competence levels of parents with children studying in K-12 and mediation in children's Internet use, family harmony and technology usage experience and examine how it differs according to the child's education level. This study was done with a representative sample consisting of 662. It was found that the competencies of the parents in preventing cyberbullying were related to positive harmonious relationships within the family, technology use experience and parental mediation. The results indicate that positive parental involvement can be predicted from higher scores in parental knowledge in cyberbullying, perception of parental competence, risk adjustment, and attribution of parental responsibility. In addition, instead of parents' restrictive mediation styles in their children's use of technology, the co-use, active mediation, and supervision styles can help reduce the likelihood of children being exposed to risks such as cyberbullying and victimization. In the multi-group analyzes made, it is seen that the research model works at the primary school level with the highest explanation rate. Moreover, it was concluded that different mediation types were effective for primary, secondary, and high school levels.