Objectives: Negative body image is a known risk factor for eating disorders. The authors investigated whether specific defense styles and/or defense mechanisms are associated with body image dissatisfaction of Korean adolescents. Methods: From August to November 2015, 1610 high school students participated in this study. They completed the Korean version of the Defense Style Questionnaire, Figure Rating Scale, Hospital Anxiety-Depression Scale-Anxiety, sunlight exposure time from 10:00 to 15:00 on weekends, and reported their height and weight. Results: A multiple linear regression analysis showed that immature defense style (β= 0.131, t=2.794, p=0.005) was significantly associated with negative body image after controlling for age, anxiety, sunlight expo-sure time on weekends (10:00 to 15:00), self-inhibiting defense style and conflict-avoiding defense style among female adolescents. Another multiple linear regression analysis showed that projection (β=0.159, t=4.030, p<0.001) was significantly associated with negative body image of female adolescents after adjusting for age, anxiety, sunlight exposure time on weekends, consumption, and omnipotence. Conclusion: High projection was associated with negative body image among female adolescents. Decreasing projection through a psychotherapeutic approach to female adolescents may help achieve proper body image and this could prevent the development of eating disorders.