This article presents initial data on the application of a pain protocol in posttraumatic stress disorder (PTSD) to assess the neural circuitry that is involved in the disorder, with a special interest in the role of the anterior cingulate cortex (ACC). Preliminary analysis demonstrated a specific and differentiated role for the ACC. Fixed affects analysis demonstrated that stimuli subjectively perceived as more painful resulted in increased activation of the caudal ACC, whereas less painful stimuli resulted in increased activation of the rostral ACC in both groups.