Attention and memory performances were studied in Persian Gulf War veterans with and without posttraumatic stress disorder (PTSD) diagnoses. Veterans diagnosed with PTSD showed relative performance deficiencies on tasks of sustained attention, mental manipulation, initial acquisition of information, and retroactive interference. Their performances were also characterized by errors of commission and intrusion. The tendency toward response disinhibition and intrusion on cognitive tasks was correlated positively with reexperiencing symptoms and negatively with avoidance-numbing symptoms. These cognitive deficit patterns are consistent with models of PTSD that emphasize the role of hyperarousal and implicate dysfunction of frontal-subcortical systems. Results suggest that intrusion of traumatic memories in PTSD may not be limited to trauma-related cognitions but instead reflects a more general pattern of disinhibition.