The second-harmonic (SH) signal generated from Ag(110), Ag(111) and Ag(100) electrodes in aqueous solutions were measured over a wide range of potentials. From the experimental data both the isotropic and anisotropic amplitudes were calculated as a function of the potential. The contributions from the bulk were also analyzed. The isotropic response was compared to the values predicted by a theoretical model based on jellium and pseudopotentials.