This study applied a theory of bystander intervention to teachers and has proven to have much utility in understanding how other bystanders may influence a teacher's direct intervention in instances of school bullying. Middle-school teachers (n = 63) completed an online survey, which utilized video scenarios, and quantitative methods were utilized in analysis. Factors analyzed in relation to direct intervention included teacher accuracy in identifying bullying behavior, intended teacher response, perception of administrator support and peer response, and self-efficacy. Results indicate that peer response (F(8, 58) = 6.067, p = 0.014) and administrator support (F(14, 58) = 6.515, p = 0.009) have significant impact on a teacher's direct intervention in incidents of school bullying. Results also suggest that all teachers do not perceive administrator support or effective peer response in incidents of school bullying.