Posttraumatic stress disorder (PTSD) is the most prevalent mental disorder arising from combat and is poised to be a considerable health risk for our military veterans. To date, there is a paucity of nursing research that examines PTSD in this vulnerable population. The purpose of this article is to demonstrate how Roy's Adaptation Model can be an effective framework for nurses to understand the phenomenon of posttraumatic stress disorder in the combat veteran population. Current research conducted on PTSD across other disciplines is highlighted within the context of Roy's model to elucidate the idea of the combat veteran as a human adaptive system and to identify gaps for future nursing research.