Posttraumatic stress disorder (PTSD) was examined as a risk factor for suicidal ideation in Iraq and Afghanistan War veterans (N = 407) referred to Veterans Affairs mental health care. The authors also examined if risk for suicidal ideation was increased by the presence of comorbid mental disorders in veterans with PTSD. Veterans who screened positive for PTSD were more than 4 times as likely to endorse suicidal ideation relative to non-PTSD veterans. Among veterans who screened positive for PTSD (n = 202), the risk for suicidal ideation was 5.7 times greater in veterans who screened positive for two or more comorbid disorders relative to veterans with PTSD only. Findings are relevant to identifying risk for suicide behaviors in Iraq and Afghanistan War veterans.