Rates of heavy drinking are consistently higher among U.S. military personnel than among civilians, particularly among young male personnel. In addressing drinking in the military, more information is needed on contextual factors influencing drinking to better understand the conditions that lead to or facilitate drinking. Results from 15 focus groups conducted with enlisted personnel at 2 Navy and 2 Marine Corps installations as part of formative research for an alcohol abuse prevention trial are reported in this article. The study explored the "drinking climate" of each installation in terms of shared attitudes and recognized norms regarding alcohol use and installation personnel's general understanding of policies concerning alcohol consumption. Analysis revealed several contextual factors that add to our understanding of drinking behaviors.