<p><i>Background</i>: Descriptive norms are commonly associated with participant drinking. However, study participants may incorrectly perceive that their peers drink about the same amount as they do, which would bias estimates of drinking homogeneity. <i>Objectives</i>: This research examined the magnitude of associations between emerging adults' reports of their own drinking and peer drinking measured the previous year by measures of (1) participants' perceptions of friends' drinking; and (2) actual drinking reported by nominated peers. <i>Methods</i>: The data are from annual surveys conducted in 2014 and 2015, Waves 4 and 5 (the first 2 years after high school) of 7 annual assessments as part of the NEXT Generation Health Study (n = 323). Associations of participant alcohol use with perceived friend use (five closest, closest male, and closest female friends), and with actual peer use. Logistic regression analyses estimated the magnitudes of prospective associations between each measure of peer drinking at W4 and participant drinking at W5.</p