The aims of the current study were to assess the factor structure of weight loss expectancy and to explain weight reduction behavior among teenagers. An anonymous questionnaire was administered to a sample of 599 adolescents. Principal components analysis identified four weight loss expectancy factors, which were labeled social confidence, adult approval, self-worth, and negative consequences. Results from regression analyses indicated that dieting frequency, diet pill use, and purging were best explained by different subsets of predictors. Overall, self-esteem, gender, and specific expectancy and knowledge variables accounted for most of the variance in measures of dieting frequency diet pill use, and purging. The findings suggest that weight management education for teenagers should emphasize self-esteem enhancement. However, curriculum planning must also address the anticipated psychosocial rewards of weight loss and attend to gender-specific concerns.