The effects of aged garlic extract (AGE) on longevity and learning and memory performances were studied in the senescence accelerated mouse (SAM). A solid diet containing 2% (w/w) AGE was given to SAM from 2 months of age. The survival ratio of SAM P8, senescence accelerated animals, treated with AGE was significantly higher than that of untreated controls. AGE, however, did not affect the life span of SAM R1, a senescence-resistant strain. AGE had no effect on body weight and motor activity. In the passive and conditioned avoidance tests, AGE markably improved a memory acquisition process in the step-down and shuttle-box tests, and also a retention process in the step-through and step-down tests in SAM P8. The beneficial effects of AGE were observed in a memory retention process in the step-down test and in an acquisition stage in lever-press test in SAM R1. These results suggest the possibility that AGE might be useful for treating physiological aging and age-related memory deficits in humans.