Ellipsometry was used to study the electroprecipitation of Ni(OH)(2) films onto mirror-finished Pt or Ni electrodes from 0.1 M Ni(NO3)(2) solution at current densities of -0.075, -0.15, -0.30, and -0.60 mA/cm(2). An automatic self-compensating ellipsometer was used to monitor in situ the as-deposited Ni(OH)(2) film properties until a charge density of 380 mC/cm(2) was passed. Plots of the measured ellipsometric parameters Delta and Psi vs. precipitation charge density revealed differences in the nature of the four films as well as the kinetics of the deposition process. The initial stage of Ni(OH)(2) deposition (up to 100 mC/cm(2)) at all current densities produced films with very similar optical and electrochemical properties. However, pronounced differences in the optical properties of the films appeared at longer precipitation times, with the films becoming less compact. Numerical analyses of the ellipsometric data provided evidence in support of a two-step electroprecipitation process, and indicated that the densities of freshly precipitated Ni(OH)(2) films fall in the range 1.25-1.50 g/cm(3), depending on the magnitude of the applied current density.