Background: Individuals with Posttraumatic Stress Disorder (PTSD) experience significant levels of psychological distress which is often moderated by social support. PTSD prevalence and symptomology gender differences tend to exist, and this may have important implications for the potential differential impact of social support. Objectives: The primary objectives of this study were to explore levels of psychological distress and social support in a sample of 364 Canadian adults reporting a PTSD diagnosis by a health professional, and to examine the link between specific social support types and psychological distress overall, and for males and females separately. Methods: Using a cross-sectional, national data file, 117 male and 247 female Canadian adults aged 20-64 reporting PTSD were profiled using the Social Provisions Scale – Short Form (SPS-SF), and the Kessler Psychological Distress Scale (K10), and compared to a sex, age and frequency matched control group without a PTSD diagnosis. Social support subtype scores were subsequently regressed onto psychological distress.Results: The PTSD sample had psychological distress scores that were more than double that of the matched control group, and were significantly lower in overall social support, and on each subscale. A diagnosis of PTSD was found to moderate the effect of social support on psychological distress, and while higher social integration and income predicted lower distress overall, higher reliable alliance scores, personal income, and lower age predicted lower distress for men, and higher social integration but lower guidance scores predicted lower distress for women.Conclusions: Social support subtypes were differentially associated with psychological distress experienced by those with PTSD depending on gender, and this may have important implications for clinical practice.