This study investigated paths to suicidal behavior in 94 civilian participants with chronic posttraumatic stress disorder (PTSD). Two statistical modeling programs, TETRAD II version 2.1 and Mplus 5.21 were used to construct a working model of suicide in PTSD. Two paths to suicidal behavior were identified. In the first path, suicidal behavior was directly associated with greater life impairment, which in turn was associated with poorer occupational and social functioning. In the second path, suicidal behavior was directly associated with depressive symptoms, which in turn were associated with more severe PTSD symptoms. Psychotropic medication, employment status, and threat to life further contributed to the model. The findings suggest that negative perceptions of functional impairment and depression are strongly associated with suicidal behavior in PTSD.