The adsorption and desorption of hydrogen sulfide on clean reconstructed Au(100)-(5x20) and sulfided gold, denoted Au(100)-(1x1)-SH, has been studied with a combination of temperature programmed desorption (TPD), low energy electron diffraction (LEED), Auger electron spectroscopy (AES) and molecular beam methods. Precursor adsorption kinetics were observed for the adsorption of H@sub 2@S on the Au(100)-(5x20) between 80 and 100 K. The H@sub 2@S adsorbs reversibly into a weakly bound physisorbed state, which desorbs at ~107 K. At 110 K reversible Langmuir adsorption was observed for H@sub 2@S on the Au(100)-(5x20). The Au(100)-(1x1)-SH was prepared by electron irradiation of H@sub 2@S adsorbed on the Au(100)-(5x20) substrate. The adsorption kinetics for H@sub 2@S on the Au(100)-(1x1)-SH exhibited Langmuir adsorption kinetics at 80 K, in sharp contrast with the precursor adsorption kinetics observed on the clean Au(100)-(5x20) surface. The TPD of H@sub 2@S from Au(100)-(1x1)-SH and H@sub 2@S adsorbed on Au(100)-(1x1)-SH showed additional features at higher temperatures which are probably associated with the disproportionation of chemisorbed HS(ad). Finally, we have identified a further sulfided gold surface, denoted Au(100)-(2x2)-S which is prepared by annealing the Au(100)-(1x1)-SH to remove adsorbed hydrogen.