Recent research has suggested that the disruption of certain neurobiological systems in association with trauma-induced stress may provide putative mechanisms for changes in neurocognitive function in association with PTSD. In this study, neurocognitive variables were examined in relation to PTSD, mild traumatic blain injury (TBI), and chronic pain (PAIN) following motor vehicle accident injury. Consistent with the well-known neurocognitive effects of mild traumatic brain injury, the TBI group performed significantly lower than the PAIN control group on measures tapping attention, verbal memory, and speeded information processing. In contrast, the idea that PTSD may be associated with neurocognitive impairment received little support. (C) 2000 Academic Press.