School bullying has become a topic of public concern and considerable research in various countries around the world in the last two decades. We summarise characteristics such as types and causes of school bullying, based on findings from various studies. We further review a variety of large-scale, school-based intervention programmes, implemented in different countries and school settings, that have been systematically evaluated. These programmes have varied substantially in their effectiveness in reducing levels of bullying at schools. Reasons for these mixed outcomes are discussed, together with suggestions for improving the effectiveness of future interventions.