This study examines the association between posttraumatic stress disorder (PTSD), in terms of the three main symptom clusters (intrusion, avoidance and arousal), and the self-report of family functioning of Vietnam veterans and the self-report of family functioning of their partners. A second objective was to determine if depression, anger and alcohol abuse mediated between PTSD symptoms and family functioning.Vietnam veterans and their partners completed a series of questionnaires as part of their participation in the inpatient and outpatient PTSD treatment program, in the Veterans Psychiatry Unit, at the Austin and Repatriation Hospital.Data from 270 veterans and partners were used in the final analyses. The PTSD subscales were initially correlated with family functioning for veterans and family functioning for partners. Then two path diagrams were constructed and analyzed using the statistical program AMOS to test for mediating effects between PTSD symptoms and family functioning. For veterans there were significant initial correlations with all three subscales of the PTSD measure. In the path analysis when the mediating variables were included only the avoidance subscale of the PTSD measure remained directly associated with family functioning. The arousal PTSD subscale was mediated by anger. The measures of depression and anger were significantly associated with poor family functioning and the anger and the avoidance subscales were significantly associated with depression. In the second set of analyses conducted on data from partners, the PTSD symptoms of avoidance and arousal were initially correlated with family functioning. When the test for mediation was conducted none of the PTSD subscales remained associated with partners' self-report of family functioning. Posttraumatic stress disorder arousal and alcohol abuse were mediated by anger for partners' self-report of family functioning.Posttraumatic stress disorder symptoms of avoidance for veterans, and comorbid symptoms of anger and depression for veterans, and anger on its own for partners appear to be important in the self-report of family functioning. These findings suggest that veterans and their partners have similar difficulties as couples with distressed relationships in the community.