Research has well-documented the relationship between posttraumatic stress disorder (PTSD) and substance use following a traumatic event. However, few studies have examined the development of PTSD in survivors who are under the influence of substances during the traumatic event. The current literature boasts mixed results; some studies find sexual assault survivors under the influence of alcohol report fewer PTSD symptoms, while other studies show survivors demonstrate higher levels of PTSD symptoms subsequent to the trauma exposure. The current study examined whether alcohol use at the time of a sexual assault or other type of trauma was associated with severity of PTSD symptoms in 1045 Kent State undergraduate students. Through anonymous online testing, participants completed the Posttraumatic Stress Diagnostic Scale (PDS), to screen and assess for the severity of PTSD symptoms and substance use at the time of the trauma. Univariate analysis of variance revealed that for all surveyed trauma types, alcohol use at the time of the trauma was associated with increased severity of PTSD symptoms (p < .001). When investigating only interpersonal types of trauma, reports of alcohol use at the time of trauma did not have a significant effect on PTSD symptoms (p = .533). The findings underscore the need to further examine the relationship between trauma exposure and PTSD when victims are under the influence of alcohol.