Two studies employing a mixed experimental design were conducted to determine if perceptions of bullying, attitudes towards victims, and students' sense of safety at school were influenced by bystanders' reactions to different types of bullying. In Study 1, 217 middle-school children were randomly assigned to read a hypothetical scenario describing a direct bullying episode. In Study 2, 376 primary-school children and 390 middle-school children were presented with scenarios describing a direct bullying episode and an indirect bullying episode. In all scenarios, the bystanders' reactions to the bullying and the gender of the victim were manipulated. Participants endorsed the prosocial behavior in favor of the victims and did not endorse pro-bullying behavior. Furthermore, they perceived passive reactions to the bullying as negative behavior. Participants showed positive attitudes towards victims, which were significantly higher at younger grade levels and among girls. Bystanders' behavior influenced both participants' perceptions of the victims and their perceived sense of safety at school. Implications for anti-bullying programs based upon the group ecology are discussed. (Contains 4 tables.)