Both affective lability and eating expectancies have been found to predict binge eating. There is the additional possibility that the joint effect of affective lability and eating expectancies incurs further risk: perhaps expectancies for affective relief from eating operate more strongly in those experiencing frequent, rapid shifts in emotion. In the current study, we tested whether such a joint effect predicts binge eating prospectively in college students. We assessed affective lability, eating expectancies, and binge eating in 358 college students at two time points during the first year of college (e.g., December and April). The interaction of affective lability and eating expectancies in December predicted binge eating 4 months later in April. The influence of eating expectancies on binge eating was stronger at higher levels of affective lability. Findings offer support to the hypothesis that risk factors may transact to further elevate risk for eating disorder behaviors.The interaction of affective lability and eating expectancies predicts binge eatingRisk factors may interact to further increase binge eatingIdentification of co-occurring risk factors may have vital treatment implications.