Simultaneous cyclic voltammetry (CV) and surface resistance (SR) measurements were employed to study the electrochemical behaviour of the nickel hydroxide-gold modified electrode. To this end, firstly, gold film electrodes of different thicknesses were synthesized, and their CV and SR responses within the potential regions corresponding to hydroxide ion adsorption (OH_ads) and gold oxide (AuO) formation in alkaline medium were analysed. Then, these gold film electrodes were modified with different nickel hydroxide surface coverages, and their CV and SR responses were compared with those of bare gold films within the same potential regions and electrolyte solution. While cyclic voltammetric responses of the bare gold film electrode and the nickel hydroxide-gold film modified electrode within the potential region -0.5 V < E < 0.35 V (SCE) are practically the same, SR responses exhibit strong differences. SR data were interpreted in terms of the field effect and size effect theories formulated to study adsorption processes at thin metallic films. With regard to the bare gold film electrode, the field effect theory allows one to conclude that within the potential region corresponding to hydroxide ion adsorption, 77% of the electron density charge of gold is involved in the hydroxide ion–gold interaction. Besides, a linear relation between the surface resistance change (DR) and the degree of oxidation (?_ox) at fixed gold film thickness (f_m), is obtained within the potential region corresponding to gold oxide formation. In agreement with the size effect theory, the DR/?_ox slope exhibits a linear dependence on f_m^-2. With regard to the nickel hydroxide-gold modified electrode, it was observed that after the reduction of OH_ads and AuO layers, at potential values more negative than -0.3 V (SCE), an increase of the surface resistance is observed which was attributed to nickel adatoms that directly interact with the gold film surface. The surface resistance increase is proportional to the nickel hydroxide surface coverage, G_Ni(OH)2. Application of the free electron model to interpret the electron scattering process at a gold surface shows that compact structures of nickel adatoms (structures diffusely reflecting conduction electrons are, on average, compensated by those reflecting specularly) are formed at a nickel hydroxide surface coverage value around 3 x 10^-9 mol cm^-2.