Cognitive and neuropsychological tests are often employed to help describe the functioning of patients with multi-infarct dementia (MID) or patients with dementia of the Alzheimer's type (DAT). In this study, the Halstead-Reitan Neuropsychological Battery (HRNB), Wechsler Adult Intelligence Scale-Revised (WAIS-R), and Wechsler Memory Scale (WMS) were completed by 20 MID patients and 62 patients with DAT. Total scores on these measures did not differentiate DAT and MID patients. Contrary to clinical observations, cognitive tasks assessing social judgment did not differentiate between the groups. However, MID patients demonstrated greater variability in test scores. Compared with DAT patients, the MID patients demonstrated better preserved memory as shown on the WMS in comparison to the WAIS-R IQ.