The present study examined associations between narcissism (total, adaptive, and maladaptive), self-esteem, and externalizing and internalizing problems in 157 non-referred adolescents (aged 14 to 18). Consistent with previous research, narcissism was positively associated with self-reported delinquency, overt aggression, and relational aggression. Maladaptive narcissism showed unique positive associations with aggression and delinquency variables, while adaptive narcissism showed unique negative associations with anxiety symptoms. In general, self-esteem was negatively related to internalizing and externalizing problems. An interaction effect was observed for self-esteem and narcissism in predicting overt aggression. Specifically, at high levels of self-esteem narcissism was significantly associated with overt aggression, whereas it was not at low levels of self-esteem. The current results add to the growing body of research on the role of narcissism in the development of adjustment problems in youth.