This study examined variation in friendship formation and friendship stability as a function of children's and their friends' victimization, overt aggression, and relational aggression. Participants were 605 pre- and early adolescents in fifth through eighth grades (M age = 12.05) assessed twice over a three-month period. Scores for stability and acquisition of same-sex reciprocated friendships were derived from unlimited friendship nominations. Peer nominations provided scores for child and friend victimization and aggression. Only victimized children experienced difficulty forming new friendships, evidence of their persistent social problems. Dissimilarity between friends on relational aggression (all children) and victimization (girls only) predicted friendship termination, however; overtly aggressive children had difficulty maintaining friendships regardless of their friends' aggression. These findings point to the importance of considering the relational context (characteristics of children and their friends) and gender when assessing friendship stability.