Cyberbullying is a topic that has attracted much attention during the last decade both in the media and in scientific discourse. Cyberbullying is defined as an electronic version of traditional bullying that encompasses a variety of different behaviors, ranging from sending offensive text messages to spreading embarrassing videos through YouTube or Facebook. Therefore, cyberbullying can be interpreted as an unfavorable by-product of the social change towards digital communication. The present thesis gives an overview of the research on traditional and cyberbullying with a focus on definition, prevalence, risk factors and consequences, and possibilities for prevention and intervention. The leading research question is whether cyberbullying is a conceptually new form of aggressive behavior or if it is comparable to traditional forms of bullying. Moreover, four additional research questions are going to be answered and discussed on the basis of results from four studies. The first study addresses the question if cyberbullying is perceived as worse than traditional bullying. Study number two examines longitudinal associations between cybervictimization and depressive symptoms. The third study explores the longitudinal link between the development of moral deficits and the development of bullying behavior (traditional and cyber). In the fourth and last study, longitudinal risk factors for becoming a cyberbully are examined. Results from these four studies are summarized and discussed within the framework of traditional bullying and cyberbullying research. The central finding of the present thesis is that cyberbullying can be considered as a new facet of a well-known problem, namely traditional bullying, rather than a conceptually new form of aggressive behavior. Therefore, cyberbullying needs to be integrated into both research on, and prevention of bullying.