This study investigated the effect of cognitive factors on competency to stand trial. Previous researchers have investigated how psychological variables --such as psychosis and intelligence--contribute to incompetency. Although several researchers have established that intelligence contributes to incompetency, very few have investigated the role of specific cognitive abilities within the realm of intelligence. This study investigated the performance of 55 defendants referred for competency restoration on neuropsychological measures. Specifically, competent defendants and incompetent defendants were compared on several measures assessing functioning in seven cognitive domains. Competent defendants performed significantly better than incompetent defendants on measures of verbal comprehension, social judgment, verbal memory, and executive functioning. Competent and incompetent defendants did not differ on attention, visual spatial skills, or nonverbal memory.