Research examining the comorbidity of posttraumatic stress disorder (PTSD) and alcohol-use disorder (AUD) suggests that individuals experiencing PTSD symptoms (PTSS) often drink alcohol as a means to self-medicate their trauma symptoms; however, little attention has been given to moderating variables that may make this association more likely. The stressor vulnerability model proposes that being male, relying on maladaptive forms of coping, and holding positive alcohol-outcome expectancies predispose individuals to engage in alcohol use when experiencing psychological distress. In the current study, sex, avoidance coping (AVC), tension-reduction expectancies (TRE), and emotional-relief drinking-refusal self-efficacy (ERDRSE) were examined as moderators of the relationship between PTSS and alcohol-related problems in a sample of 144 undergraduates. Results indicated that males reporting high levels of TRE exhibited a stronger positive relationship between PTSS and alcohol-related problems than was present for males reporting low levels of TRE and for females reporting either high or low levels of TRE. In addition, a significant positive relationship between PTSS and alcohol-related problems was observed for individuals reporting high levels of TRE and low levels of ERDRSE, but not for individuals reporting high levels of TRE and high levels of ERDRSE, low TRE-low ERDRSE, or low TRE-high ERDRSE. Assessment of these vulnerability factors in traumatized youth and young adults may serve as a useful means of identifying individuals at risk for the development of alcohol-related problems.