Self-assembled monolayers (SAMs) of n-alkanethiols on mechanically polished polycrystalline nickel substrates are presented. The effects of several preparation conditions of the surface upon the metal/sulfur bonds and monolayer properties are evidenced. Of particular importance are the electrochemical reduction of the native oxide, the thiol concentration (10 -3 versus 10 -1 M), and the nature of the solvent (ethanol, acetonitrile, n-heptane, toluene, and carbon tetrachloride).