Bullying has been identified as a worldwide problem and has attracted great attention from the media, researchers, educators, and parents in the past few decades. This introductory article describes the prevalence and demographic differences for both traditional bullying and cyberbullying among U.S. adolescents. Then it reviews risk and protective factors, potential impacts, and findings on the relationship between traditional bullying and cyberbullying. It ends with a discussion on the effectiveness of current prevention and intervention programs. (Contains 1 table.)