This article reports a survey study on postdivorce coparenting and its relationships with children’s well-being in Hong Kong. Based on data from 142 resident parents and 84 children, the results revealed that interparental conflict and triangulation of children within parental conflict adversely affected children’s well-being, whereas interparental support fostered children’s well-being. Parental communication and interparental support coexisted simultaneously with parent conflicts. These conflicting effects make postdivorce coparenting a mixed blessing for children. Fortunately, residential parent-child intimacy and quality parenting by both parents protected children’s well-being from the effects of negative relational dynamics. Promoting postdivorce coparenting should always accompany effective interventions in conflict resolution, the renegotiation of growth-enhancing boundaries among family members, the support of parental functioning and individual recovery of both parents, and the facilitation of noncompetitive parental involvement of nonresident parents.