Often obese adolescents are stigmatized by their peers at school. The resultant psychological and emotional problems could exacerbate a negative cycle of maladaptive coping and further weight gain, which could eventually increase students' resistance to physical activity and diet interventions. One obesity bias intervention involves blame reduction; however, this approach has not been effective with adults to reduce deep seated implicit biases and might make obese adolescents appear non-normal. An alternative strategy would be provision of positive information to enhance receptivity (LaGreca & Bearman, 2000). The purpose of the present study was to compare the effectiveness of two interventions on reducing obesity bias among secondary school students. Participants included 224 seventh and eighth graders (88 boys and 136 girls; 19 European Americans, 193 African Americans, 12 others) enrolled in physical education classes from an urban school. In each class period, participants were randomly assigned to one of the three conditions. Within condition, they were randomly assigned into three learning groups. The intervention condition focused on consciousness raising, blame reduction, and perspective taking. The second condition, focused on consciousness raising and providing positive information. Participants in control condition engaged in regular cooperative learning activities in their assigned groups. The interventions lasted about one hour each time for three days in PE classes. A package of all instruments was administered to participants before and after intervention. All negatively worded items were reverse coded, and all coefficients alphas were acceptable ranging from 0.75 to 0.81. Correlations were conducted to examine the relationships between implicit biases, BMI, stereotypes, and explicit biases. MANOVAs were conducted to examine whether participants had any explicit and implicit obesity biases. One-way MANOVAs with repeated measures using learning groups as the unit of analysis were used to examine whether participants would have less obesity biases than those in the control condition. The results indicated that adolescents showed moderately high implicit biases and some explicit biases toward overweight peers. Participants who had lower BMI were likely to assign higher scores on the implicit smart/stupid and good/bad subscales. It is suggested that thinner adolescents tend to be more implicitly biased. The hypothesis that both interventions would reduce explicit and implicit biases was not supported. However, inspection of the means indicated positive trends for pre- to post-intervention compared to those in control condition. Further research is warranted to replicate the present study at a longer time period and in multiple school sites. Keyword(s): obesity issues, physical education PK-12, research