This research examined similarities and differences between gambling activities, with a particular focus on differences in gambling frequency and rates of problem gambling. The data were from population-based surveys conducted in Canada between 2001 and 2005. Adult respondents completed various versions of the Canadian Problem Gambling Index (CPGI), including the Problem Gambling Severity Index (PGSI). A factor analysis of the frequency with which different gambling activities were played documented the existence of two clear underlying factors. One factor was comprised of Internet gambling and betting on sports and horse races, and the other factor was comprised of lotteries, raffles, slots/Video Lottery Terminals (VLTs), and bingo. Factor one respondents were largely men; factor two respondents were more likely to be women and scored significantly lower on a measure of problem gambling. Additional analyses indicated that (1) frequency of play was significantly and positively related to problem gambling scores for all activities except raffles, (2) the relationship between problem gambling scores and frequency of play was particularly pronounced for slots/VLTs, (3) problem gambling scores were associated with playing a larger number of games, and (4) Internet and sports gambling had the highest conversion rates (proportion who have tried an activity who frequently play that activity).