The purpose of this study was two fold. First, the study examined whether constructs from the Theory of Planned Behavior (TPB: Ajzen, 1985, 1991) play a role in predicting consumption of alcohol mixed with energy drinks (AmED) among college undergraduates. Second, the study also estimated the prevalence of AmED consumption and provided a better understanding of the theoretical and demographic variables associated with AmED consumption among a large sample of college undergraduates located at a public university in the Southeastern United States. The study used a cross-sectional study design (n=676) to administer a 39-item survey assessing alcohol use, energy drink (ED) use, and the consumption of mixing alcohol with energy drinks (AmED). As part of this assessment, students responded to theoretical questions about AmED consumption in the last 30 days. Analyses exploring the univariate significance of theoretical and demographic predictors revealed that all of the TPB constructs were significant univariately. Additionally, the demographic predictors of class year and Panhellenic affiliation were also univariately significant (p<.05). However, when incorporated into a logistic regression model, the TPB constructs of behavioral intention and attitude were the only significant predictors (p<.05) of AmED consumption among undergraduate college students. Subjective norms and perceived behavioral control were no longer significant. Furthermore, logistic regression analyses also showed that the demographic variables of age, sex, place of residence, and Panhellenic affiliation also did not predict AmED consumption, while class year remained a significant predictor (p<.05) of AmED consumption. Lastly, a mediation analyses was conducted using logistic regression techniques. Results showed that behavioral intention is a complete mediator for the effect of subjective norms on AmED consumption and is also a partial mediator for the effect of attitudes on AmED consumption in the last 30 days. Despite the cross-sectional nature of this study, its primary strength was its application of theory to better understand AmED use among college undergraduates. Findings from this study have implications for future intervention development aimed at targeting preventive efforts among college populations.