Nearly half of college students engage in binge drinking, and blackouts (i.e., episodes of periodic memory loss) represent one common consequence of this behavior. Although researchers have begun to understand the extent to which students black out, little is known about why they do so. We conducted two studies to further our understanding of this risky health behavior. In Study 1, we conducted face-to-face interviews (N = 19) to explore students' blackout experiences. Our findings suggest that students recognize that blacking out is an unhealthy behavior; however, because such a recognition contradicts group norms about alcohol consumption, it causes them to experience dissonance, which they manage via a variety of rationalization strategies. We investigated these findings more systematically through an online survey in Study 2, in which students (N = 254) reported on their own and others' beliefs and behaviors about blacking out. Our results indicate that many of the rationalization strategies students identified in Study 1 were grounded in fallacious reasoning. We discuss the collective implications of these findings for future interventions addressing students' excessive drinking behaviors.