Researchers have utilized the Bystander Intervention Model to conceptualize bullying bystander behavior. The five-step model includes Notice the Event, Interpret the Event as an Emergency, Accept Responsibility, Know How to Act, and Decision to Intervene. The purpose of this study was to examine outcomes of an evidence-based bystander training within the context of the Bystander Intervention Model among middle school students (N = 79). We used a quasi-experimental design to examine differences in outcomes between bystanders and non-bystanders. We also assessed which of the steps were uniquely associated with post-training defending behavior. Results indicated a significant increase in Know How to Act for both groups. In contrast, we found increases in Notice the Event, Decision to Intervene, and defending behavior among bystanders only. Finally, Notice the Event and Decision to Intervene were uniquely associated with post-training defending behavior. We discuss implications of these findings for counselors.