BACKGROUND: Posttraumatic stress disorder (PTSD) is one of the most commonly observed stress-related conditions following combat exposure and its effective prevention is a high health-care priority. Reports of peritraumatic reactions have been shown to be highly associated with PTSD among combat exposed service members. However, existing instruments measuring peritraumatic symptoms were not specifically developed to assess combat-related peritraumatic stress and each demonstrates a different peritraumatic focus. We therefore developed the Peritraumatic Behavior Questionnaire (PBQ), a new military-specific rating scale focused upon the wide range of symptoms suggestive of combat-related peritraumatic distress in actively deployed Service Members. This study describes the development of the PBQ and reports on the psychometric properties of its self-rated version (PBQ-SR).METHODS: 688 Marine infantry service members were retrospectively assessed by the PBQ-SR within the scope of the Marine Resiliency Study after their deployment to war zone. Participants have been additionally assessed by a variety of questionnaires, as well as clinical interviews both pre and post-deployment.RESULTS: The PBQ-SR demonstrated satisfactory internal consistency, convergent and discriminant validity, as well as high correlation with trait dissociation prior to deployment. Component analysis suggested a latent bi-dimensional structure separating a peritraumatic emotional distress and physical awareness factor. The PBQ-SR total score showed high correlation to general anxiety, depression, poorer general health and posttraumatic symptoms after deployment and remained a significant predictor of PTSD severity, after controlling for those measures. The suggested screening cut-off score of 12 points demonstrated satisfactory predictive power.CONCLUSIONS: This study confirms the ability of the PBQ-SR to unify the underlying peritraumatic symptom dimensions and reliably assess combat-related peritraumatic reaction as a general construct. The PBQ-SR demonstrated promise as a potential standard screening measure in military clinical practice, while It's predictive power should be established in prospective studies.