Cyberbullying is one of the most common threats an adolescent might face online with serious negative consequences at the social, emotional and educational level. Despite the intense study of the phenomenon over the past decade, most researchers ask for new directions in research that will focus on risk and protective factors. This study attempted to investigate the predictive effect of internet use, parental mediation, school-bullying and victimisation, gender and empathy on cyberbullying and cybervictimisation in two measurements, 4 months apart. Data collection was conducted using a self-report questionnaire. Four hundred and forty secondary school students, aged 12-14, participated in the study. The students were randomly selected from six public schools located in the Greater Metropolitan Area of Thessaloniki in Greece. Results showed that involvement in traditional bullying as a victim or as a perpetrator is the factor with the highest predictability for cyberbullying and cybervictimisation, which also remains stable across time. This finding points to the urgent need for designing and implementing programmes against all forms of bullying both offline and on line.