Objective: To study actual and perceived substance use in Canadian university students and to compare these rates with US peers. Participants: Students (N = 1,203) from a large Canadian university. Methods: Participants were surveyed using items from the National College Health (NCHA) Assessment of the American College Health Association questionnaire. Results: Alcohol was the most common substance used (65.8%), followed by marijuana (13.5%) and cigarettes (13.5%). Substance use and norms were significantly less than the NCHA US data. Overall, respondents generally perceived the typical Canadian student to have used all 3 substances. Perceived norms significantly predicted use, with students more likely to use alcohol, cigarettes, or marijuana if they perceived the typical student to use these substances. Conclusions: Similar to their US peers, Canadian university students have inaccurate perceptions of peer substance use. These misperceptions may have potentially negative influences on actual substance use and could be a target for intervention. Further research examining the cross-cultural differences for substance abuse is warranted. (Contains 3 tables and 1 figure.)