The current study used multiple informants to examine the impact of relationship experiences with parents and romantic partners on relational security among early adolescent girls, over a 1-year period. Seventy-one early adolescent girls and their primary caregivers participated at Time 1 and 1 year later (Time 2). Findings suggest that both parental and romantic relationship experiences impact relational security during early adolescence. The most consistent findings from the current study were the ability of romantic rejection to alter the relational security of early adolescent girls as well as the importance of parent–adolescent attachment security in predicting comfort with intimacy.