Exercise improves cognitive impairments induced by transient cerebral ischemia and modulates synaptic adhesion molecules. In this study, we investigated effects of long-term treadmill exercise on cognitive impairments and its relation to changes of synaptic cell adhesion molecule (SynCAM) 1/2/3 in the hippocampus after 5 min of transient cerebral ischemia in aged gerbils. Animals were assigned to sedentary and exercised groups, given treadmill exercise for 4 consecutive weeks from 5 days after transient ischemia and evaluated cognitive function through passive avoidance test and Morris water maze test. SynCAM 2 protein levels were determined in the hippocampus by western blot. In addition, neuronal and synaptic changes were examined by NeuN immunohistochemistry, and SynCAM 1/2/3 and MAP2 double immunofluorescence, respectively. We found that transient cerebral ischemia led to neuronal death in the CA1 area and dentate gyrus, and impaired conflictive function; however, treadmill exercise improved ischemia-induced memory impairment. In addition, SynCAM 1/2/3 expression in the hippocampus was significantly decreased in the sedentary group after transient cerebral ischemia; however, SynCAM 2 protein level was significantly increased in the ischemic group with exercise. These results suggest that long-term treadmill exercise improves memory impairment through the restoration of decreased SynCAM 1/2/3 expression in the hippocampus induced by transient cerebral ischemia in the aged gerbil.