Bullying, a subcategory of aggressive beha-vior, is encountered regularly by children and adolescents in the context of schools worldwide (for an overview see Smith et al., 1999; Whitney and Smith, 1993). In Canada, self-report data indicate that 8 to 9% of elementary school children are bullied frequently (i.e., once or more a week) and about 2 to 5% of students bully others frequently (Bentley and Li, 1995; Charach, Pepler, and Ziegler, 1995). Among adolescents, at the secondary school level, rates are somewhat higher, with 10 to 11% of students reporting that they are frequently victimized by peers, and another 8 to 11% reporting that they frequently bully others (Vaillancourt and Hymel, 2001). Observational studies show that, although peers are present in most bullying situations (85 to 88%), they seldom intervene on behalf of victims (11% to 25% of the time) (Atlas and Pepler, 1998; Craig and Pepler, 1997) and many students just watch, while others even join in (O'Connell, Pepler, and Craig, 1999). Although bullying is a common experience for students around the world, it is a complex social problem that can have serious negative consequences for both bullies and victims (see Salmivalli, 1999; Smith and Brain, 2000). The negative effects of bullying are well documented, not only in terms of the psychological harm that is inflicted upon victims, but also in terms of the maladaptive outcomes for children who engage in bullying. Studies from countries around the globe tell us that bullying behavior predicts later criminality and delinquency (Olweus, 1991; Pulkkinen and Pitkanen, 1993) and is associated with both externalizing and internalizing diffi-culties (see Juvonen and Graham, 2001; Kaltiala-Heino, Rimpela, Marttunen, Rimpela, and Rantanen, 1999; Kaltiala-Heino, Rimpela, Rantanen, and Rimpela, 2000; Swearer and Doll, 2001). Victimization is associated with both physical and mental health difficulties (Rigby 2001; Slee, 1995) as well as school disliking and avoidance that, in turn, can affect academic performance (Hodges and Perry, 1996; Juvonen, Nishina, and Graham, 2000). A growing body of evidence further suggests that children who are both bullies and victims are at even greater risk than children who are either bullies or victims (Austin and Joseph, 1996; Haynie et al., 2001; Nansel et al., 2001). Perhaps most alarming is the number of teens who have ended their own lives because of both bullying and victimization (see Marr and Field, 2001). Researchers, educators, parents, and commu-nities are struggling to understand how it is that our adolescents, most of whom we believe to be good, caring individuals, behave in ways that condone and maintain bullying, with a substantial number of students engaging directly in bullying behavior or failing to do anything to stop it. The picture that has emerged is a complicated one. A growing body of research suggests that bullying and peer harassment emerge as a result of a number of different factors, not just one (e.g., Baldry and Farrington, 2000; Espelage, Bosworth, and Simon, 2000; Pepler, Craig, and O'Connell, 1999; Swearer and Doll, 2001). Such problems are not solely the result of individual characteristics of the student, poor home environments, ineffective parenting and school practices, "bad influences," peer pressure, or exposure to violent media, etc. but rather, reflect a complex interplay among these factors. In this regard, we concur with Swearer and Doll (2001) in arguing for an ecological pers-pective on bullying in an effort to understand how both individual characteristics of the bully and victim as well as family, peer, school, cultural, and community factors each contributes to the likelihood of bullying and peer harassment. In light of this perspective, we have become increas-ingly convinced of the importance of the peer group and the social climate of the school in terms of their contributions to bullying and peer harass-ment. Accordingly, we have worked directly with schools to examine how the school climate, as reflected by student attitudes and beliefs about bullying, contribute to the maintenance of bully-ing problems in schools. Student attitudes and beliefs can play a significant role in supporting bullying behavior.