Using a cross-sectional survey of a random sample of 7,945 college undergraduates, the authors report on the association between having received Green Dot active bystander behavior training and the frequency of actual and observed self-reported active bystander behaviors as well as violence acceptance norms. Of 2,504 students aged 18 to 26 who completed the survey, 46 percent had heard a Green Dot speech on campus, and 14 percent had received active bystander training during the past 2 years. Trained students had significantly lower rape myth acceptance scores than did students with no training. Trained students also reported engaging in significantly more bystander behaviors and observing more self-reported active bystander behaviors when compared with nontrained students. When comparing self-reported active bystander behavior scores of students trained with students hearing a Green Dot speech alone, the training was associated with significantly higher active bystander behavior scores. Those receiving bystander training appeared to report more active bystander behaviors than those simply hearing a Green Dot speech, and both intervention groups reported more observed and active bystander behaviors than nonexposed students. (Published Abstract)