Objective: This study examined posttraumatic stress disorder (PTSD) as a potential moderating variable in the relationship between social support and elevated suicide risk in a sample of treatment-seeking Iraq and Afghanistan War Veterans. Method: As part of routine care, self-reported marital status, satisfaction with social networks, PTSD, and recent suicidality were assessed in Veterans (N 5 431) referred for mental health services at a large Veteran Affairs Medical Center. Logistic regression analyses were conducted using this cross- sectional data sample to test predictions of diminished influence of social support on suicide risk in Veterans reporting PTSD. Results: Thirteen percent of Veterans were classified as being at elevated risk for suicide. Married Veterans were less likely to be at elevated suicide risk relative to unmarried Veterans and Veterans reporting greater satisfaction with their social networks were less likely to be at elevated risk relative to Veterans reporting lower satisfaction. Satisfaction with social networks was protective for suicide risk in PTSD and non-PTSD cases, but was significantly less protective for veterans reporting PTSD. Conclusions: Veterans who are married and Veterans who report greater satisfaction with social networks are less likely to endorse suicidal thoughts or behaviors suggestive of elevated suicide risk. However, the presence of PTSD may diminish the protective influence of social networks among treatment-seeking Veterans. Depression and Anxiety 27:1001–1005, 2010.