This study examines young adults' experiences with relational aggression among friends and romantic partners. Results suggest that relational aggression occurs more frequently among romantic partners than among friends. A gender difference in relational aggression emerged in the romantic context (females were more aggressive), but no gender difference was found in the friendship context. Relationship exclusivity and normative beliefs about relational aggression predicted aggressive behavior across contexts, while rumination predicted relational aggression in the romantic context but not in the friendship context. Implications of these findings, as well as directions for future research, are discussed.