The purpose of this research is to test how adolescent girls’ narcissistic traits—characterized by a need to impress others and avoid ego‐threat—influence acute adverse effects of thin‐ideal exposure. Participants (11–15 years; total N = 366; all female) reported their narcissistic traits. Next, in two experiments, they viewed images of either very thin or average‐sized models, reported their wishful identification with the models (Experiment 2), and tasted high‐calorie foods in an alleged taste test (both experiments). Narcissism kept girls from wishfully identifying with thin models, which is consistent with the view that narcissistic girls are prone to disengage from thin‐ideal exposure. Moreover, narcissism protected vulnerable girls (those who experience low weight‐esteem) from inhibiting their food intake, and led other girls (those who consider their appearance relatively unimportant) to increase their food intake. These effects did not generalize to conceptually related traits of self‐esteem and perfectionism, and were not found for a low‐calorie foods outcome, attesting to the specificity of findings. These experiments demonstrate the importance of narcissism at reducing girls’ thin‐ideal vulnerability. Girls high in narcissism disengage self‐protectively from threats to their self‐image, a strategy that renders at least subsets of them less vulnerable to the thin‐ideal.