Reflective opposite sex norms are behavior that an individual believes the opposite sex prefers them to do. The current study extends research on this recently introduced construct by examining estimates and influences of reflective norms on drinking in a large high-risk heterosexual sample of male and female college students from two universities. Both gender and Greek-affiliation served as potential statistical moderators of the reflective norms and drinking relationship. All participants (N=1790; 57% female) answered questions regarding the amount of alcohol they believe members of the opposite sex would like their opposite sex friends, dates, and sexual partners to drink. Participants also answered questions regarding their actual preferences for drinking levels in each of these three relationship categories. Overall, women overestimated how much men prefer their female friends and potential sexual partners to drink, whereas men overestimated how much women prefer their sexual partners to drink. Greek-affiliated males demonstrated higher reflective norms than non-Greek males across all relationship categories, and for dating partners, only Greek-affiliated males misperceived women's actual preferences. Among women however, there were no differences between reflective norm estimates or the degree of misperception as a function of Greek status. Most importantly, over and above perceived same-sex social norms, higher perceived reflective norms tended to account for greater variance in alcohol consumption for Greeks (vs. non-Greeks) and males (vs. females), particularly within the friend and sexual partner contexts. The findings highlight that potential benefits might arise if existing normative feedback interventions were augmented with reflective normative feedback designed to target the discrepancy between perceived and actual drinking preferences of the opposite sex.