Ventricular volume estimates and an index of cerebral atrophy were obtained from computerized axial tomography scans of patients with presenile or senile dementia of probable Alzheimer's type. These measures were used to examine the correlation between morphological brain change and performance on the Wechsler Adult Intelligence Scale (WAIS) and the Wechsler Memory Scale (WMS). Despite ventricular volumes in excess of 60% larger than normal, no significant correlations were found between ventricular size and WAIS or WMS performance. The index of pericerebral atrophy did correlate negatively with various WAIS measures, particularly Performance IQ, and some aspects of WMS performance. Results suggest that in Alzheimer's disease, pericerebral atrophy measures, but not ventricular dilation, correlate with intellectual decline and certain aspects of memory impairment.