A novel Au(III)-N-heterocyclic carbene organometallic complex supported by two N-heterocyclic carbene (NHC) ligands was synthesized from Au(SMe2)Cl and 1-methy1-2-pyridin-2yl-2H-imidazo[1,5-a]pyridin-4-ylium hexafluorophosphate via a Ag intermediate. X-ray crystallography revealed the first example of a square planar geometry adopted by a Au(III) species stabilized by two NHCs and two chloride ligands. The aforementioned Au(I)- and Au(III) NHC complexes were found to be more potent than cisplatin against the HCT 116, HepG2, A549, and MCF7 cell lines.