A method is described to relate brain morphology and neuropsychological disturbances such as aphasia. By mapping lesions with computerized tomography onto a grid model of five brain slices, it is possible to compare aphasiological information and lesion site by data processing, allowing the quantitative and qualitative manipulation of a large number of data. The soundness of the method is investigated in a pilot study on the localization of aphasic disturbances. Data processing was performed on a preliminary group of 70 patients with different aphasic syndromes (Broca, Wernicke, and global aphasics with and without recurring utterances). The results confirmed the findings of older studies, with the typical locus of Wernicke's aphasia being Wernicke's area. In conformity to more recent studies, the main lesion for Broca aphasics was found to be in the insular cortex, with a relatively important participation of the frontal white matter. The implications of this refined method for more vigorous aphasiological and neuropsychological research are briefly indicated.