Abstract: Objective: A considerable number of studies have reported an increased frequency of suicidal behaviors among individuals diagnosed with posttraumatic stress disorder (PTSD). This study aims, first, to provide a comprehensive systematic review and meta-analysis of the association between a PTSD diagnosis and frequency of suicidality and, second, to examine the role of comorbid depression in the association between suicidality and PTSD.Methods: Searches of Medline (June 2010), EMBASE (June 2010), PsycINFO (June 2010), PILOTS (June 2010), and Web of Science (June 2010) were conducted to identify studies that examined the association between PTSD and suicidality. The studies had to include an effect size of the association between PTSD and suicidality to be included in the meta-analysis. Sixty-three studies were eligible for inclusion in the meta-analysis. Overall and subgroup effect sizes were examined.Results: A highly significant positive association between a PTSD diagnosis and suicidality was found. The PTSD-suicidality association persisted across studies using different measures of suicidality, current and lifetime PTSD, psychiatric and nonpsychiatric samples, and PTSD populations exposed to different types of traumas. Comorbid major depression significantly compounded the risk for suicide in PTSD populations.Conclusion: The current meta-analysis provides strong evidence that a PTSD diagnosis is associated with increased suicidality. The crucial role of comorbid major depression in the etiology of suicidality in PTSD is also supported.