Napping behavior is largely unexplored in adolescents. This study compared the dysfunctional cognitions and negative affect of adolescent nappers and non-nappers. Participants were 231 adolescents (mean age, 17.7 years) who completed sleep, cognition, and negative affect questionnaires. Adolescent nappers demonstrated significantly more dysfunctional cognitions (P = 0.01), anxiety (P < 0.01), and stress symptoms (P < 0.01), when compared to non-nappers. In contrast, no significant difference was found for depression (P = 0.18). Furthermore, adolescent nappers with more severe dysfunctional cognitions demonstrated greater negative affect (all P < 0.05). The present study is one of the first to demonstrate a link between adolescent napping, dysfunctional cognitions, and negative affect.