The purpose of this study was to implement a weight-related teasing prevention program and evaluate the effectiveness of the program among adolescents. One hundred forty-three students in 7th-grade in health classes at the middle school were asked to participate in the study. The weight-related teasing prevention program was implemented as part of health curriculum at a middle school in Utah. At pretest, 47% of participants admitted that they had experienced bullying in the past as victims. Specifically, verbal bullying (47%) was the most frequently reported form of bullying experienced among participants. Girls were more likely to experience physical bullying than boys. There were statistically significant differences in scores on weight-related teasing effect (M = 0.30, 95% CI [0.46, 0.56], t (101.497) = 2.344, p = 0.021), competency teasing ( M = 1.27, 95% CI [0.39, 2.18], t (117.546) = 2.784, p = 0.01) and victimization of competency teasing (M = 0.67, 95% CI [0.37, 0.97], t (116.916) = 4.471, p = 0.00) between boys and girls. Interestingly, girls scored higher than boys on weight-related teasing, competency teasing and victimization of competency. On the other hand, male mean scores on body esteem and self-esteem were higher than female mean scores on those variables. Verbal bullying (e.g., teasing) was the most frequently reported form of bullying in this study. Girls' bullying involvement was significantly demonstrated by data. However, it is suggested to educate about bullying among both girls and boys. After the program, the number of students who were bullied was reduced by 7% (From 42% to 35%). The prevalence rate of bullies was also decreased from 18% to 14%. Girls reported higher mean scores on victimizations of weight-related and competency teasing. On the other hand, girls' mean scores on IBSS decreased more than boys' after the intervention program suggesting that they experienced more improvement from the intervention. In conclusion, the intervention program effectively increased participants' body esteem and self-esteem. Although female participants tended to report more victimization from teasing (weight and competency), they showed a stronger positive effect by the end of the intervention program. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]