GABA (1, 4-aminobutanoic acid, γ-aminobutyric acid) is the major inhibitory neurotransmitter in the brain and is essential for the overall balance between neuronal excitation and inhibition. GABA influences neurons via a large number of receptor subtypes which are grouped on the basis of their pharmacology under three major classes of receptors: GABAA, GABAB, and GABAC receptors. GABAA and GABAC receptors are ligand gated ion channels, while GABAB receptors are Gprotein coupled receptors. This Perspective compares and contrasts aspects of the medicinal chemistry and molecular biology of GABAA and GABAC receptors. The molecular diversity of these ligand gated ion channels represents important challenges for medicinal chemists in the design of subunit-specific therapeutic agents.