Recent findings indicate that glucose administration enhances memory processes in rodents. This study examined the effects of glucose on memory in humans. After drinking glucose- or saccharin-flavored beverages, college-aged and elderly humans were tested with modified versions of the Wechsler Memory Scale. Beverages and tests were administered in a counter-balanced, crossover design, enabling within subject comparisons. The major findings were: (1) glucose enhanced memory in elderly and, to a lesser extent, in young subjects; and (2) glucose tolerance in individual subjects predicted memory in elderly, but not in young subjects on both glucose and saccharin test days.