This article reviews the extant published and unpublished studies that estimate the prevalence of adolescent gambling problems in North America. The nine nonduplicative studies identified by our literature search included data collected from more than 7700 adolescents from five different regions of the United States and Canada. In addition to comparing the conceptual and methodological differences that exist among these studies, this article employed a meta-analytic strategy to synthesize prevalence estimates from the existing studies. This analysis revealed that within a 95 percent confidence interval, between 9.9% and 14.2% of adolescents are at risk of developing or returning to serious gambling problems. Similarly, between 4.4% and 7.4% of adolescents exhibit seriously adverse compulsive or pathological patterns of gambling activity. Finally, the discussion proposes a generic multi-level classification scheme to reconcile the divergent classification methods and data reporting strategies. This new multi-level approach to reporting gambling prevalence will facilitate interstudy comparisons among existing estimates of gambling prevalence and help to provide a general data reporting system for future research.