The electrochemistry of gold(III) mono- and bis-quinoxalinoporphyrins was examined in CH2Cl2 or PhCN containing 0.1 M tetra-n-butylammonium perchlorate (TBAP) before and after the addition of trifluoroacetic acid to solution. The investigated porphyrins are represented as Au(PQ)PF6 and Au(QPQ)PF6, where P is the dianion of the 5,10,15,20-tetrakis(3,5-di-tert-butylphenyl)porphyrin and Q is a quinoxaline group fused to a beta,beta'-pyrrolic position of the porphyrin macrocycle; in Au(QPQ)PF6 there is a linear arrangement where the quinoxalines are fused to pyrrolic positions that are opposite each other. The porphyrin without the fused quinoxaline groups, Au(P)PF6, was also investigated under the same solution conditions. In the absence of acid, all three gold(III) porphyrins undergo a single reversible Au-III/Au-II process leading to the formation of a Au(II) porphyrin which can be further reduced at more negative potentials to give stepwise the Au(II) porphyrin it-anion radical and dianion, respectively. However, in the presence of acid, the initial Au-III/Au-II processes of Au(PQ)PF6 and Au(QPQ)PF6 are followed by an internal electron transfer and protonation to regenerate new Au(III) porphyrins assigned as Au-III(QPQH)(+) and Au-III(QPQH)(+). Both protonated gold(III) quinoxalinoporphyrins then undergo a second Au-III/Au-II process at more negative potentials. The electrogenerated monoprotonated monoquinoxalinoporphyrin, Au-II(PQH), is then further reduced to its it-anion radical and dianion forms, but this is not the case for the monoprotonated bis-quinoxalinoporphyrin, Au-II(QPQH), which accepts a second proton and is rapidly converted to Au-III(HQPQH)(+) before undergoing a third Au-III/Au-II process to produce Au-II(HQPQH) as a final product. Thus, Au(P)PF6 undergoes one metal-centered reduction while Au(PQ)PF6 and Au(QPQ)PF6 exhibit two and three Au-III/Au-II processes, respectively. These unusual multistep sequential Au-III/Au-II processes were monitored by thin-layer spectroelectrochemistry and a reduction/oxidation mechanism for Au(PQ)PF6 and Au(QPQ)PF6 in acidic media is proposed.