Background: Problem drinking is a perennial concern in the US fire service. A large literature has documented the importance of addressing alcohol norms in intervention research. The purpose of this study was to explore alcohol norms in a national cohort of firefighters (FFs) to inform intervention development in this occupational group. Methods: Data were from a national online survey of career and volunteer FFs (N = 674). Participants were recruited through national fire service listservs and a database of FFs who had agreed to be contacted for research. Results: When asked about “acceptable” levels of alcohol consumption, FFs on average suggested levels which exceeded public health guidelines. Further, approximately half of career and volunteer FFs believed that, at least under some circumstances, drinking until intoxicated was normative. When asked how long should elapse between a FFs last drink and reporting for duty, the average suggested lag was 11.2 hours (sd = 4.6). However, among male volunteer FFs who reported heavy drinking, the average was 6.68 hours (sd = 4.77). Conclusions Given the high prevalence of heavy and binge drinking in the fire service, it is not surprising that the alcohol norms found in this study were consistent with a culture of drinking. Participants' reports of alcohol use among their peers were consistent with the actual prevalence of problem drinking. Thus, education and prevention efforts in this occupation should focus on changing norms about alcohol use, including linking heavy drinking to other health and safety issues they face.