It is well established that the obese gene product, leptin is an important circulating satiety factor that signals nutritional status to specific hypothalamic nuclei involved in body weight regulation. However, evidence is accumulating that, in addition to its pivotal role as an adiposity signal, leptin is a multi-faceted hormone that plays an important role in a plethora of CNS functions. In this review we summarize the recent advances made in leptin biology, with particular focus on its potential role as a cognitive enhancer and antiepileptic agent in the hippocampus.