The purpose of this study was to investigate the moderating effects of a size of the friendship network and quality of friendship on the associations between mutual antipathy and maladjustment. The subjects were 678 fifth- and sixth-grade primary school children who were recruited from a public school in Bucheon City. The Peer Nomination Inventory was used to assess mutual antipathy, peer victimization, social withdrawal, aggression, and the friendship network. The children were given a classroom roster and asked to nominate up to three classmates who fit each description. Additionally, the children reported the quality of their friendships using the Friendship Quality Scale. Each child was asked to indicate his or her one best friend and rate how accurately a sentence describe done of their best friends on the scale. The results revealed that the friendship network and friendship quality significantly moderated the relationships between mutual antipathy and social withdrawal, and peer victimization. The magnitude of the association between mutual antipathy and social withdrawal was not significant for large friendship networks and high quality friendships. Although mutual antipathy was significantly associated with peer victimization, the association was stronger at lower levels than at higher levels of the friendship network and quality. However, there was no moderating effect of the friendship network and quality on the association between mutual antipathy and aggression. A large friendship network and high quality friendship could be protective factors among those who have mutual antipathy in peer groups.