Effects that growth hormone (GH) may exert on brain function have received attention among many researchers over the past two decades. In patients with impaired pituitary production of this hormone replacement therapies have been demonstrated not only to compensate for GH effects in peripheral organs but also to improve several behaviors related to the brain. For instance, available data suggests that subjects treated with GH have experienced significant improvements in concentration, memory, depression, anxiety and fatigue. Also, pituitary-ectomized male rats showing decreased ability in tasks related to learning and memory are seen to improve their performance in these items following GH replacement. The mechanism underlying these beneficial effects of GH has been the subject of studies in many laboratories. An important aspect in this regard is the discovery of specific receptors in various brain regions related to the functional anatomy of several behaviors affected by the hormone. The aim with this article is to review current knowledge on GH receptors in the brain and discuss possible mechanism for the action of the hormone in its ability to affects brain function.