Perceived drinking motives of social network members appear to influence emerging adults’ alcohol use indirectly through their own drinking motives. Ascertaining the accuracy of motive perceptions can determine the relevance of social norm interventions for drinking motives and the utility of egocentric versus direct-reporting social network designs. As part of a larger study, 60 emerging adults (70% female; mean age = 21.57) reported cross-sectionally on their own drinking motives and the drinking motives of a peer. Peers were recruited and reported on their drinking motives. Regression analyses utilizing the truth and bias model indicated social, coping-with-anxiety, and coping-with-depression motives exhibited accuracy. Participants also overestimated peers’ social, enhancement, and conformity motives. Coping-with-depression and enhancement motives exhibited assumed similarity. Most motive perceptions were heavily or singularly influenced by bias. Whether to include actual and/or perceived motives in social network research designs should be carefully considered.