The theory of planned behavior (TPB) was used, modified, and extended to predict dieting intention and behavior. Female undergraduates ( n = 256) responded to a survey assessing variables from the TPB and additional predictor variables. Seventy-eight of these participants also completed a follow-up questionnaire 3 months later that assessed their subsequent weight-loss behavior. A model was developed for dieting using path analysis to assess the most significant paths to intention to diet and follow-up dieting. In the final predictor model, 77% of the variance in intention to diet and 46% of the variance in follow-up dieting were explained. The strongest predictor of intention to diet was direct attitude, and the strongest predictor of follow-up dieting was prior dieting. This study also included a confirmatory analysis of the dieting model (n=117). Approximately 2/3 of the paths were confirmed, and 72% of the variance in intention was explained.