The preparation and application of a simple silver/silver sulfate reference electrode for an aqueous solution, which can be used as an alternative in chloride-free systems, is reported. The electrodes are prepared by galvanostatic oxidation of silver wire in sulfate solution: the potential stability with time is measured as a function of the current density and overall charge used in oxidation. The electrode potential is also measured in a wide concentration range of sulfate and chloride solutions and an explanation of the observed stability is presented. The range of optimal conditions, crucial for the correct electrode operation, is discussed. © 2012 The Royal Society of Chemistry.