Data from student-athletes at 15 colleges and universities (N = 4,258) document extensive misperceptions of peer drinking norms and their association with personal quantity of alcohol consumed. Regardless of actual drinking norms at each school, student-athletes commonly overestimated the alcohol consumption norms (both quantity and frequency levels) of both male and female athlete peers. Perception of the male student-athlete drinking norm was the strongest predictor of drinks personally consumed at parties and bars for both genders in comparison with the effects of the actual male and female norms and demographic variables. The perceived female norm was also a strong predictor of female but not male consumption.