The deposition of nano- and micro platinum particles onto semiconductor substrates attracts much interest due to the improvement produced both in the stabilization of electrodes and in the catalysis of hydrogen evolution. The use of the potentiodynamic technique to form platinum particles on doped silicon surfaces was tested at room temperature from an acidic solution of hexachloroplatinate (IV). Nano- and micrometric techniques indicated that, by controlling the number of voltammetric scans it was possible to obtain dispersed particles of different size. The extension of the electrodeposition can be monitored by the in situ voltammetric response, since the simultaneous reactions of hydrogen on platinum were found to be useful to follow the platinum deposition. Impedance spectroscopy was found also to be another sensitive technique to detect platinum on the substrate.