Abstract: This study examined the links between sibling relational aggression and other sibling relationship qualities (i.e., intimacy, negativity, and temporal involvement) and broader parenting dynamics. Participants included 185 adolescent sibling pairs and their mothers and fathers. Data were gathered during home interviews and a series of nightly phone calls with adolescents and parents. Findings revealed that sibling relational aggression was related to sibling intimacy and negativity. In addition, connections emerged between relational aggression and qualities of the parent-child relationship, parents’ differential treatment, and parents’ strategies for handling sibling conflict.