This paper examines the effectiveness of school-based drug prevention programs in preventing illicit drug use. Our paper reports the results of a systematic review of the evaluation literature to answer three fundamental questions: (1) do school-based drug prevention programs reduce rates of illicit drug use? (2) if they do, what features are characteristic of effective programs? and (3) do these effective program characteristics differ from those identified as effective in reviews of school-based drug prevention of licit substance use (such as alcohol and tobacco)? Using systematic review and meta-analytic techniques, we identify the characteristics of school-based drug prevention programs that have a significant and beneficial impact on ameliorating illicit substance use (i.e. narcotics) among young people. We find that successful intervention programs typically involve high levels of interactivity, time-intensity, and universal approaches that are delivered in the middle school years. These program characteristics aligned with many of the effective program elements found in previous reviews exploring the impact of school-based drug prevention on licit drug use (i.e. alcohol and tobacco). Contrary to these past reviews, however, our analysis suggests that the inclusion of booster sessions and multifaceted drug prevention programs have little impact on preventing illicit drug use among school-aged children. Limitations of the current review and policy implications are discussed. Keywords: school-based drug prevention, illicit drugs, substance use, meta-analysis, systematic review.