Studies testing the effects of self-affirmation on alcohol-related cognitions and behavior in university students have produced equivocal results. Because self-affirmation is a motivational technique (i.e., designed to reduce defensive processing) it may need to be supplemented with volitional techniques, such as forming if-then plans, to translate positive intentions into behavior. Participants (N = 348) were randomly assigned to conditions in a 2 (self-affirmation) × 2 (implementation intention) between-participants factorial design. Participants completed a self-affirmation task (i.e., values essay) or not, read a summary about the health risks of binge drinking (8/6 units for men/women), and then completed an implementation intention task (i.e., forming if-then plans) or not. Participants then completed measures of message derogation, perceived risk, and intention as well as alcohol consumption 1 week later. All main and interaction effects for self-affirmation were nonsignificant. In contrast, participants who formed implementation intentions (vs. not) reported drinking fewer units of alcohol and engaged in binge drinking less frequently at 1-week follow-up. Additional analyses revealed that affirming a social value attenuated the effect of self-affirmation on intention, but augmented the effect of implementation intentions on behavior. Overall, the findings provide additional evidence for the positive effects of implementation intentions but question the use of self-affirmation to reduce alcohol consumption in university students.