The silver surface screening effects by specifically adsorbed halide anions in the electrocatalytic reduction of a model organic bromide (acetobromoglucose) have been studied by cyclic voltammetry on controlled mono- and polycrystalline silver surfaces in acetonitrile +0.1 M tetraethylammonium perchlorate medium as a function of the concentration c(X) of added TEAX (X = Cl, Br, or I, TEA, tetraethylammonium). The reduction peak potentials, E-p, are regularly shifted in the negative direction with increasing c(X), typically tending to an asymptotic value for c(X) approximate to 0.1 M. Several literature models describing adsorption/desorption equilibria have been applied to justify the above experimental E-p versus e(X) trends (being logarithmic in the iodide cases) for the three halides and the four silver surfaces tested. (C) 2003 Elsevier Science B.V. All rights reserved.