Glucose utilization appears to play a role in memory, and patients with Senile Dementia of the Alzheimer Type (SDAT) show particular abnormalities of the glucose system. The present study examined the effects of glucose administration on memory in subjects with mild SDAT and age-matched controls. SDAT subjects demonstrated greater overall increases in blood glucose levels following glucose administration. Normal subjects whose blood glucose levels returned to near baseline following glucose administration showed facilitated memory performance, whereas SDAT subjects whose blood glucose levels remained elevated showed significant improvement following glucose administration. The results suggest that impaired glucose regulation contributes to memory impairment in SDAT.