1. The GABAergic neurotransmission has been implicated in the modulation of many neural networks in forebrain, midbrain and hindbrain, as well as, in several neurological disorders. 2. The complete comprehension of GABA system neurochemical properties and the search for approaches in identifying new targets for the treatment of neural diseases related to GABAergic pathway are of the extreme relevance. 3. The present review will be focused on the pharmacology and biochemistry of the GABA metabolism, GABA receptors and transporters. In addition, the pathological and psychobiological implications related to GABAergic neurotransmission will be considered.