In this study, the authors examined whether exposure to relational victimization was associated with children's thoughts, emotions, and behavior in an unfamiliar, challenging peer context. Children (110 girls, 96 boys; mean age = 10.13 years, SD = 1.16) reported on their exposure to relational victimization by peers. Following a challenging interaction with an unfamiliar peer, children reported on their beliefs about their interaction partners and their social goals (i.e., focus on getting to know their partner vs. impressing their partner) during the interaction. Coders rated children's emotion and behavior regulation and the quality of the dyadic context. Results from hierarchical linear modeling analyses reveal that relational victimization predicted maladaptive social-cognitive processes (i.e., more negative peer beliefs and a heightened performance goal orientation) and heightened emotion and behavior dysregulation. Several of these effects were particularly salient in the context of a conflictual dyadic interaction. This research provides insight into impairments associated with relational victimization that may contribute to the emergence and/or perpetuation of peer difficulties. (Contains 4 tables and 1 footnote.)