Pd-P thin films over carbon steel were prepared by electroless deposition, using sodium hypophosphite as reducing agent. The influence of the plating conditions, on the properties of the coatings is investigated in detail. The deposits morphology was assessed by Scanning Electron Microscope and Atomic Force Microscopy imaging, their compositions and respective elements distribution determined by Energy Dispersive Xray Spectrometry and structural information obtained by X-ray diffraction. It has been observed that the amount of co-deposited P depends on both the deposition time and the employed NaH(2)PO(2) Concentration, which in turn dictates the degree of amorphicity of the so-prepared Pd-P layers. The modified electrodes electrochemical behaviour, evaluated by cyclic voltammetry in alkaline media, revealed that the hydrogen adsorption/ absorption process and the hydrogen evolution reaction are enhanced on alloys with phosphorus content below 10 at.%. (c) 2007 Elsevier B.V. All rights reserved.