Although impairment in cognitive functioning is theoretically linked to the presence of post-traumatic stress disorder (PTSD), the actual impact of this disorder on neuropsychological performance remains largely unknown. While a modest amount of empirical attention has been directed toward examining the neuropsychological correlates of PTSD, several methodological problems, most notably small sample sizes and the resulting lack of power, have greatly restricted generalizability of findings. The present study examined the neuropsychological performance pattern of Vietnam veterans with PTSD (n = 241) as compared to those with generalized anxiety disorder (n = 241) and no history of psychiatric diagnosis (n = 241). A one-way MANOVA revealed no significant differences among the groups on any of the dependent measures of cognitive functioning, including the Wechsler Adult Intelligence Scale-Revised Block Design subtest, the California Verbal Learning Test, the Rey-Osterrieth Complex Figure Drawing Test, and the Paced Auditory Serial Addition Test. The results are reconciled as they relate to previous research examining the theoretical constructs of PTSD, clinical applications, and directions for future research.