The present study examines the relationships among the degrees of internalization of media messages, self-consciousness, and dieting behaviors in females from childhood to young adulthood. A total of 422 elementary, junior and senior high school, and college students completed an anonymous questionnaire. The perceived media pressure to lose weight and information on thinness obtained from the media increased with school levels, especially from junior to senior high schools. Multiple regression analyses revealed that the perceived media pressure to lose weight predicted the level of dieting behaviors in the students across all school levels. For senior high school students, public self-consciousness also explained dieting behaviors, whereas private self-consciousness was related to dieting behaviors in the students in other school levels. The findings of the present study suggest that psychoeducational programs to prevent eating problems include elementary school girls as well as pay attention to heightened tendency to focus on how they look to others as one of the risk factors in high school girls.