In recent decades there has been a progressive increase in concern and research into the problems of peer aggression, both in the educational setting and more recently, online. The present study sought to explore sex differences in traditional bullying and cyberbullying, since current literature has not reached a consensus in how bullying involvement could be moderated by sex. The sample consisted of 3,174 adolescents aged 12-17 years old who completed a paper survey which included the European Bullying Intervention Project Questionnaire and the European Cyberbullying Intervention Project Questionnaire. The main results found no differences in cyberbullying rates for boys and girls. In the case of bullying, there were more bully-victims among the boys, but no differences were found in the pure victims or pure perpetrators. When analysing the specific bullying behaviours suffered or perpetrated, several differences were found. However, said differences were discrete and it seems that there are not distinctly differentiated bullying patterns, which discourages the use of clearly differentiated preventive strategies for boys and girls.