This study investigated gender differences in a sample of outpatient, treatment-seeking individuals (N=84) with comorbid alcohol dependence and post-traumatic stress disorder (PTSD). Assessments included substance use severity, trauma history, PTSD symptomatology, and comorbid psychiatric disorders. Men reported an earlier age of onset of alcohol dependence, greater alcohol use intensity and craving, and more severe legal problems due to alcohol use. Women reported greater exposure to sexually related traumas, greater frequency and intensity of avoidance of trauma-related thoughts and feelings, and greater social impairment due to PTSD. Women were more likely than men to demonstrate higher rates of other anxiety disorders and test positive for cocaine at treatment entry. PTSD more often preceded alcohol dependence in women than in men. The results illustrate a number of gender differences that may shed light on etiologic models of comorbid alcohol dependence and PTSD.