Background: There is evidence that some of the symptoms included under the current diagnostic criteria for PTSD are not unique to PTSD and instead represent general distress. This study attempted to delineate the nonspecific and specific components of PTSD by examining the relation of PTSD symptoms to trauma exposure and demoralization in a cohort of National Guard soldiers deployed to Iraq. Methods: Data were collected from a cohort of 348 combat deployed National Guard soldiers participating in the readiness and resilience in National Guard soldiers (RINGS) study. Current DSM-IV PTSD diagnoses and trauma exposure were determined 6 to 12 months following soldiers' return from deployment using the Clinician Administered PTSD Scale. Level of trauma exposure (as measured by a combat exposure scale), demoralization and self-reported PTSD symptoms were assessed with self-report questionnaires. Results: Dysphoria symptoms had the weakest relation with trauma exposure and the strongest relation with demoralization. In addition, these symptoms had high rates of endorsement in a group of soldiers without trauma exposure. Intrusions were strongly related to trauma and were significantly higher in the group with trauma exposure compared to the no-trauma group. Limitations: These findings may not generalize to survivors of other types of trauma, service members from other era's, or even service members from different regions or military branches who have different demographic and duty characteristics. Conclusions: Emphasizing symptoms of PTSD that are strongly related to trauma exposure will be important for the differential diagnosis of PTSD.