The electrochemical behaviour of the Ce, La and Nd oxy ions in MgCl2-NaCl-KCl eutectic was studied using cyclic voltammetry, chronopotentiometry, square wave voltammetry and electrochemical impedance spectroscopy. It has been deduced that the lanthanides are present as REOCl (RE = Ce, La, Nd) in the electrolyte and the reduction of oxychloride ion takes place in a single step according to the reaction. REO+ + le(-) --> REO (RE = Ce, La, Nd) The reduction of REO+ was found to be reversible at lower scan rates but quasi-reversible at higher scan rates beyond 75 mV s(-1). The diffusion coefficients of the rare earth oxy ions evaluated using Berzins Delahay equation were comparable and found to be similar to 10(-5) cm(2) s(-1). A single cathodic peak was observed in the square wave voltammograms at lower concentrations of the oxy ion but at higher concentrations, an additional peak was observed at a lower cathodic peak potential which is attributable to the adsorption of the product. (C) 2007 Elsevier B.V. All rights reserved.