The effect of such electroplating conditions as current density, thiourea (TU) concentration, temperature and pH on the sulphur content of NiS(x) deposited electrodes has been systematically studied using fractional factorial design and response surface methodology. Fractional factorial analysis indicates that the main and interaction effects of TU concentration and current density are the key variables influencing sulphur content in a NiS(x) deposit. Empirical models for sulphur content and hydrogen evolution overpotential are fitted and plotted, using central composite experimental design, as contour diagrams in order to facilitate comparison with experimental sulphur content trends and hydrogen evolving activity. The results show that, for deposits containing > 12 wt % sulphur content, hydrogen evolving activity increases with increasing sulphur content, while for those possessing < 12 wt % sulphur content, hydrogen evolution overpotential decreases with increasing electroplating current density.