Posttraumatic stress disorder (PTSD) can develop after a traumatic event or events. Although it is most often associated with military personnel exposed to the trauma of combat, it can also disproportionately affect vulnerable American Indian and Alaskan-Native (AI/AN) populations. Because alcohol use disorders (AUDs) also have a disproportionate impact on AI/ANs, this study compared both lifetime PTSD and past-year AUD among AI/ANs and non-Hispanic Whites (NHWs).