Nonmedical cannabis is legal in Canada and several U.S. states. Displacing the illegal market is a primary goal of legalization; however, there are little data on factors that predict consumers’ transition from the illegal to the legal market. The current study aimed to examine reasons for purchasing illegal cannabis. In both years, the most commonly reported barriers to legal purchasing were price (Canada: 35%–36%; United States: 27%) and inconvenience (Canada: 17%–20%; U.S.: 16%–18%).