Being the victim of school bullying is associated with many negative outcomes, including depression, anxiety, substance abuse, school refusal, and suicide. Peer bystanders are present in the majority of bullying situations and bystander intervention has been found to be very important in ending a bullying incident. However, most of the time bystanders do not step in to help the victim. The present study investigated the impact of parent and family influences on children’s bystander behavior. Seventy-three third- through sixth-grade students were given a questionnaire that asked about their behavior in bullying situations (engaging in bullying behavior, helping or encouraging the bully, defending the victim, or staying away from the situation altogether). Their mothers completed three questionnaires that evaluated symptoms of depression, quality of the parent-child relationship, and parent responses and experiences of anger. Key findings were: (a) parents who were more frustrated with their relationship with their children had children who were less likely to help their peers and were more likely to stay out of the incident. (b) children whose parents were less satisfied with their school were more likely to engage in bullying behavior; (c) the way parents expressed and controlled their own anger predicted whether or not their child would defend a peer; and (d) older children were both more likely to defend their peers and more likely remain uninvolved.