A cuprite (Cu2O)-modified carbon paste electrode was prepared and applied to the study of iodide sorption on cuprite, according to the ‘preconcentration–voltammetric detection’ sequence. The effects of pH, accumulation time, iodide concentration and the presence of various concentrations of chloride in the medium, on the preconcentration process, were investigated. The uptake of I− species at pH<7 was observed to occur according to a surface precipitation mechanism, involving the generation of Cu(I) species due to the reaction of protons with Cu2O. The use of a Cu2O-modified electrode was found to be efficient for the determination of the sorption mechanism and for the screening of the experimental conditions allowing an optimum uptake of I− species by Cu2O.