Nguyen HV - In this quasi-experimental difference-in-differences and triple-differences study, the researcher determined the impact of banning electronic cigarette (e-cigarette) sales to minors in Canada on e-cigarette use among youths. The mechanisms by which a ban might be related to their e-cigarette use were also explored. Data from the nationally representative Canadian Tobacco, Alcohol and Drugs Survey (2013-2017) and Canadian Student Tobacco, Alcohol and Drugs Survey (2014-2017) were utilized. Findings revealed that a significant decrease in the rate of increase in e-cigarette use by youths was achieved by banning e-cigarette sales to minors. However, the overall rise in e-cigarette use was not reversed by this policy alone. Supplementing this policy with other measures that can decrease young people’s wish to get e-cigarettes through social sources was recommended. An illustration of such a measure is a ban on e-cigarettes with flavors that appeal to youths and children.