Electro-oxidation of Ni(poly) in 0.5 M aqueous KOH solution at various polarization potentials (E p) up to 0.5 V vs. reversible hydrogen electrode, for polarization times (t p) up to 2 h, and at 285 ≤ T ≤ 318 K leads to the formation of a thin layer of α-Ni(OH)2. Interfacial capacitance measurements show that the Ni(poly) electrode covered with a layer of α-Ni(OH)2 can be completely reduced back to its metallic state by applying a negative-going potential scan with a lower potential limit of −0.2 V. An increase of E p, t p, and/or T results in an increase of the thickness of the α-Ni(OH)2 layer, which, however, never exceeds two monolayers. The electrochemical formation of α-Ni(OH)2 follows a direct logarithmic growth kinetic law. The results reported in this contribution and their interpretation imply that other oxide growth theories, such as the Langmuir-type adsorption, the point defect model, the electron tunneling, or the nucleation-and-growth model, are not applicable to the growth of α-Ni(OH)2. The potentiostatic growth of α-Ni(OH)2 on Ni(poly) is successfully treated by applying the interfacial place-exchange mechanism and the associated kinetic law.