This study investigated the predictive relations between externalizing behavior, peer preference and friendship quantity, and bully status and victim status among children becoming acquainted with one another for the first time. Children ages 6.8–9.8 years (24 with Attention-Deficit/Hyperactivity Disorder; 113 typically developing; 72 girls) attended a 2-week summer day camp grouped into same-age, same-sex classrooms with previously unacquainted peers. Externalizing behavior (via parent and teacher ratings) was measured before the start of camp; peer preference and friendship quantity (via peer nominations) were measured in the middle of camp, and bully status and victim status (via peer nominations) were measured at the end of camp. Low peer preference mediated the positive association between externalizing behavior and bully status. Both peer preference and friendship quantity moderated the relation between externalizing behavior and bully status as well as between externalizing behavior and victim status; whereas high peer preference protected against both bully status and victim status, friendship quantity protected against victim status but exacerbated bully status. Some gender differences were found within these pathways. Peer preference, compared to friendship quantity, appears to have a more consistently protective role in the relation between externalizing behavior and bully status as well as victim status.