This paper assesses the impact of an educational program designed by the Federal Trade Commission to teach advertising literacy to children ages 8-12. In a randomized experiment, children who played the program’s instructional game scored significantly higher on an ad literacy test than students who did not play the game - approximately 9 percentage points higher on a 25-question test. The treatment group’s advantage was evident on every question of the exam and remained virtually unchanged after controlling for demographic imbalances across groups. Features of the sample and the exam constrain the generalizability of results, however. In addition, a higher rate of attrition among those assigned to the treatment group introduces the possibility of unmeasured differences confounding our treatment-effect estimate. We discuss the implications of each challenge and offer a more-conservative estimate of Admongo’s impact using an intent-to-treat approach. Notwithstanding these limitations, our study stands out as one of only a small number to quantify the impact of an ad-literacy intervention using a randomized experiment.