Growth hormone (GH) receptors (GH-Rs) are widely expressed in the CNS and previous reports claim that GH can improve mood and cognition in the elderly. Nevertheless, only a few studies have investigated the function of GH in the brain. In this study, the effect of intrahippocampal injection of GH on memory impairment has been evaluated in an animal model of Alzheimer’s disease (AD). Aged Wistar male rats (350-400 g, 18-20 months old) were randomly divided into 4 following groups (7 in each): control healthy aged; AD; AD+vehicle; and AD+GH. AD was induced by bilateral injection of ibotenic acid (5μg.0.5μl-1, each side). A guide cannula was implanted in the right hippocampus under stereotaxic surgery for injection of GH (10, 20 and 40 μg.2μl-1, during 8min, twice daily, 9.00AM and 3.00 PM, for 7 days). All rats were trained in Morris water maze for spatial memory evaluation. Escape latency and travel distance to find hidden platform did not differ between AD and AD+vehicle groups, while it was reduced significantly in AD animals treated with GH in a dose dependent fashion compared with vehicle group (p<0.05). These results suggest that intrahippocampal injection of GH can improve memory in rats with AD.