A method for the deposition of palladium on the vast surface of porous silicon from aqueous solutions of PdCl2 is described. The deposited Pd and the porous silicon substrate have been characterized using X-ray absorption fine structure (XAFS) spectroscopy. It is found that deposition can be carried out in a controlled manner, that the deposited Pd is metallic, and that the oxidation-reduction reaction responsible for the reductive deposition of Pd from PdCl2(aq) takes place at specific surface sites.