Background and aims: Though women make up roughly one third of all problem gamblers, research has typically focused on male problem gamblers. Recent research has started to shift its attention toward the importance of gender. However, studies rarely attempt to understand gender differences in problem gambling or subject these differences to thorough multivariate analyses. To address some of the gaps in our knowledge of gender differences, we examine whether patterns of gambling behavior and psychological factors mediate the relationship between gender and problem gambling. Methods: We use logistic multiple regression to analyze two large Canadian datasets-the 2005 Ontario Prevalence Survey and the 2007 Canadian Community Health Survey. Results: Variables found to mediate the relationship between gender and problem gambling are the type(s) of game(s) played (in the 2005 Ontario Prevalence Survey) and the number of games played (in the 2007 Canadian Community Health Survey). Conclusions: Men are more likely to be problem gamblers than women, and this gender difference is understandable in terms of differences in patterns of gambling behavior. We conclude that men experience problems because they play riskier games and women experience problems because they prefer chance-based games, which are associated with significantly higher odds of problem gambling. We specify the three main ways that women's reasons for gambling-to escape or for empowerment-translate into chance-based games.