This alcohol abuse prevention project was designed as a two year program beginning October 1, 2011 involving development and administration of surveys at three time points (initial, interim, and final surveys) to Airmen ages 18-24. The initial survey provided the data for determining the first set of actual norm messages and served as a baseline for subsequent assessments of program impact. At each base personnel posted base-specific media created by the project. The bases involved in this project were assigned to an initial intervention condition (social norms messages designed to reinforce positive norms and reduce misperceptions of the norm along with traditional harm reduction information), a control/delayed intervention condition beginning after the second survey, or a continuous control condition (harm reduction information only). The interim survey served the purpose of short term impact analyses and also as an intervention mechanism providing interactive feedback at social norms intervention bases. An additional round of media was distributed after the interim survey. The final survey was used to assess the overall impact of the intervention at social norms bases and produce additional social norms messages and media for all participating bases. Results of the initial survey demonstrated that misperceptions of peer norms for alcohol use were pervasive across all bases. Airmen typically believed (erroneously) that their same age peers at the base most commonly supported and engaged in heavier and more risky drinking than was actually the case and these misperceptions were highly associated with the actual problem drinking that was personally reported. Results following the social norms intervention demonstrated significant reductions in misperceived norms and in personal problem drinking behaviors. These reductions were specifically associated with exposure to social norms messages at the base controlling for other demographic characteristics of Airmen and bases. Alcohol related misconduct data reported by each participating base provided additional supporting evidence of significant positive impact of the intervention.