Bullying is not a new phenomenon in schools although the increasing prevalence among students involved has gone from occasional to usual (Cerezo, 2008). The reasons for these aggressive behaviours can be due to many factors depending on different contexts of people’s social backgrounds. On the other hand, the fast technology evolution in our society has allowed technologies to be a part of minors’ daily lives without concern for their previous education in its responsible use, allowing students to become vulnerable targets for someone who uses mobile phones or Internet to harass them. This research presents the following objectives: i) analyze the reasons bullies and victims use to justify their implication in cyberbullying; ii) contrast the reasons in cyberbullying depending on sex and school ownership; and iii) compare the perception between school bullying and cyberbullying. The resulting finds confirm the presence of cyberbullying between pupils in the last grades of Primary School, pointing at provocation as the main cause that justified the electronic aggression with major prevalence in public schools. However, on the contrary to our predictions, cyberbullying is viewed as a more damaging phenomenon when compared to traditional bullying, which encourages us to go into this topic in depth, and also into its prevention in schools.