Background: Little research has focused on factors influencing teachers' decisions about whether and how to intervene in bullying incidents. Such factors have the potential to influence the role of teachers as agents in counteracting bullying. Aims: To examine: (a) whether moral orientation predicts teachers' responses to bullying, (b) the role of perceived seriousness of an incident in moderating responses to bullying and (c) factors that are important to teachers when deciding whether to intervene. Sample: Primary, middle and high school teachers (N = 127) were recruited during staff meetings at five schools. Methods: Moral orientation was measured using a modified version of Caputo's (2000) Sanctioning Voice Index (SVI); other questionnaires were specifically designed for this study. Correlational and hierarchical multiple regression analyses examining how moral orientation and seriousness predict teachers' responses to bullying were performed. Results: As anticipated, care moral orientation predicted a problem-solving response, while justice orientation predicted a rules-sanctions response. Care and justice orientations also interacted to predict rules-sanctions, but not problem-solving responses. However, seriousness of an incident accounted for the majority of variance (46% for rules-sanctions and 40% for problem-solving responses). Seriousness did not moderate the relationship between moral orientation and responses to bullying. Conclusions: While teachers' moral orientation does impact upon the kinds of responses to bullying they choose, seriousness of the incident is more important. However, seriousness as perceived by teachers may not be consistent with impact on students. Implications for teacher education and policy are discussed.