The assessment of brain impairment is important in the vocational rehabilitation of persons with neuropsychological dysfunction. To determine the sensitivity of the General Aptitude Test Battery (GATB) to lateralized cerebral dysfunction compared to neuropsychological evaluation, 79 epileptic subjects were assigned to one of three groups (generalized impairment, right hemisphere impairment, or left hemisphere impairment). Subjects had previously been administered neuropsychological evaluations and GATBs. Group status was used as the dependent variable, and GATB-V (verbal aptitude) scores were compared with GATB-S (spatial aptitude) scores as an independent variable. It was found that the derived variable, the GATB-V score minus the GATB-S score, used as an additional independent variable, differentiated the right-impaired from the left-impaired and the generalized groups at statistically significant levels. It was not possible to distinguish the left from the generalized impaired group. No significant findings were observed on the other GATB scales. Results suggest that the comparison of the GATB-V with the GATB-S has some value in identifying persons who have demonstrated a lateralization of neuropsychological difficulties to the right cerebral hemisphere. While the differences between GATB scores for the right and left impaired groups were not statistically significant, the possibility that these groups may respond in a differential manner to the GATB on the whole suggests that vocational aptitude batteries may help rehabilitation counselors identify individuals with possible brain impairment. (JAC)