OBJECTIVE: The authors investigated a broad range of memory functions for stimuli unrelated to trauma to determine whether symptoms such as intrusive memories might reflect an underlying cognitive deficit unrelated to the psychological content of the traumatic memory in patients with posttraumatic stress disorder (PTSD). METHOD: The authors measured the intellectual functioning of 20 male combat veterans with PTSD and 12 normal comparison subjects using the WAIS and evaluated them for performance on memory using the California Verbal Learning Test. RESULTS: Veterans with PTSD showed normal abilities in the functions of initial attention, immediate memory, cumulative learning, and active interference from previous learning. However, these veterans showed a circumscribed cognitive deficit, manifested by the presence of substantial retroactive interference and revealed by a significant decrement in retention following exposure to an intervening word list. CONCLUSIONS: The data suggest that patients with PTSD may have fairly specific deficits in the monitoring and regulation of memory information.