The present study investigated the relations of self-reported and peer-nominated relational aggression (RA) with self-esteem and narcissism among 43 at-risk 16- to 18-year-olds. Self-reported and peer-nominated RA were positively intercorrelated, and each was positively correlated with narcissism. An interaction between self-esteem and narcissism predicted peer-nominated RA, such that narcissism was related to peer-nominated RA particularly for individuals with high self-esteem. Maladaptive, but not adaptive, narcissism uniquely predicted peer-nominated RA. The implications and limitations of this study for research on adolescent self-perception and RA are discussed. (Contains 2 tables, 1 figure, and 1 footnote.)