BACKGROUND: This study updates prevalence estimates of gambling-related disorders in the United States and Canada, identifies differences in prevalence estimates among population segments, and identifies changes in prevalence over the past 25 years. METHOD: A meta-analytic strategy guided the synthesis of 180 estimates derived from 146 prevalence studies. RESULTS: Prevalence estimates among adolescent samples were significantly higher than estimates among adult samples for both clinical (level 3) and sub-clinical (level 2) measures of disordered gambling within both lifetime and past-year time frames. Among adults, level 3 prevalence estimates continue to increase significantly. CONCLUSIONS: Membership in youth, treatment, and prison population segments is significantly associated with experiencing gambling-related disorders. Understanding sub-clinical gamblers provides a meaningful opportunity to lower the public health burden associated with gambling disorders. Prospective studies of incidence are necessary to determine whether the prevalence of disordered gambling continues to increase among the adult general population and how adolescent gambling experiences change as this cohort ages.