Background: Consumption of fast food, as a consequence of the modern industrial society, has increased in recent years among teenagers and young people. The purpose of this study was to investigate the effect of fast food consumption on female students in Yazd University of Medical Sciences based on the Prototype/Willingness Model. Methods: In this descriptive-analytic study, 245 female dormitory students were selected from Yazd University of Medical Sciences by stratified sampling from six dorms. Data were collected using a valid, reliable, and self-reporting questionnaire including demographic information and constructs of Prototype/Willingness Model. To analyze the data, correlation, regression, and ANOVA were applied using SPSS18. Results: Participants' maximum scores of intention with regard to non-consumption of fast foods, subjective norms, attitude, willingness, and prototype were 57, 53, 51, 67.5, and 66.2 percent, respectively. Intention to non-consumption of fast foods had a positive significant correlation with subjective norms, attitude, willingness, and prototype of fast food consumption. The combination of attitude and subjective norms accounted for 0.17 percent of the variance in intention. Moreover, attitude was the most significant predictor of intention (β = 0.38). Conclusion: According to the predictability of attitudes towards behavioral intention about fast food consumption, the individuals' negative attitudes should be enhanced towards fast food consumption in designing education programs for youth.