Posttraumatic stress disorder (PTSD) is a prevalent anxiety disorder that is often undetected among primary care patients. The Department of Veterans Affairs has implemented the Primary Care-PTSD Screen (PC-PTSD) to screen for PTSD; however, minimal research has examined its utility. This study was designed to assess the diagnostic accuracy of the PC-PTSD among veterans who had served since 9/11/2001, including operations in Afghanistan (Operation Enduring Freedom) and Iraq (Operation Iraqi Freedom). Signal detection analyses were used to evaluate the performance of the PC-PTSD and two other screens, the Davidson Trauma Scale (DTS) and the SPAN, in a sample of 220 veterans with military service since 9/11/2001. The reference standard for PTSD was Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) diagnosis based upon structured clinical interview. The impact of demographic variables on test performance was examined. A cutting score of 3 on the PC-PTSD maximized efficiency (85%; sensitivity=0.83; and specificity=0.85). Although analyses supported the utility of the PC-PTSD (area under the curve (AUC)=0.875), the measure was outperformed by both the DTS (AUC=0.944) and the SPAN (AUC=0.931). Results suggest that the PC-PTSD is an acceptable screen for PTSD among veterans. Within primary care settings, the PC-PTSD may be most advantageously employed in the context of staged screening, given the measure's relative susceptibility to false positives.