In this paper, we have reviewed our results about S adsorption on Au(111) surfaces derived from electrochemical, in situ scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS) and surface X-ray diffraction (SXD) measurements. The combination of these techniques allowed us to obtain a complete description of the S/Au(111) interface. The correlation between S/Au(111) and alkanethiolate/Au(111) interfaces in NaOH solutions is discussed, revealing the key role of the S-Au bond in determining the structure and the adsorption/desorption kinetics for these systems. (C) 2004 Elsevier Ltd. All rights reserved.