Ni-RE (RE = Y, Ce, Pr and Sm) crystalline alloys have been characterized by means of microstructural and electrochemical techniques in view of their possible application as electrocatalytic materials for the hydrogen evolution reaction (HER). The microstructure of the electrodes has been investigated by optical and electron microscopy. The electrocatalytic efficiency has been evaluated on the basis of electrochemical data obtained from Tafel curves and a.c. impedance measurements carried out in 1 M NaOH solution at 298 K. The microstructural features play a fundamental role in determining the electrocatalytic activity of the investigated alloys. The overall experimental data indicate that interesting electrocatalytic performances are obtained with Ni94Pr6 and Ni95Ce5 electrodes, which show the highest activities towards the HER. (C) 2003 Elsevier Ltd. All rights reserved.