The neuroendocrine control of appetite has great importance in the maintenance of the homeostasis of an organism. The anatomic base of the appetite regulating system consists of the neurons localized in several hypothalamic nuclei i.e. the arcuate nucleus, paraventricular nucleus, ventromedial nucleus, dorsomedial nucleus, lateral hypothalamic areas, and suprachiasmatic nucleus. The functional elements of this system constitute the neuronal factors synthesized in these hypothalamic centres. Generally, they can be divided into two groups: orexigenic factors, which stimulate appetite and anorexigenic factors, which inhibit food intake. The orexigenic and anorexigenic systems in the hypothalamus are linked both morphologically and functionally. This information supports the hypothesis of the existence of the interconnected appetite-regulating network localized in the hypothalamus. The localization of orexigenic-producing nerves and their receptors overlaps with sites containing receptors for anorexigenic factors, therefore confirming their reciprocal interactions. To the most important components of the appetite-regulating network belongs the neuronal system of NPY, which integrates the final pathway regulating food intake. It seems that such numerous orexigenic and anorexigenic pathways are too redundant and their functions are often doubled. However, it is a characteristic feature of the biological mechanism regulating a key function of an organism, which works as “the security system” for it’s continuously changing needs in the internal and external environment.