A modified carbon paste electrode was used for the simultaneous determination of Zn, Cd, Pb, Cu and Hg. Trace metal preconcentration was effected by selective retention on Amberlite IRC 718 chelating resin as an electrode modifier, with subsequent measurement by differential-pulse voltammetry. Peak potentials for he reoxidation of these metals occur at - 1.05, - 0.80, - 0.48, - 0.24 and 0.06 V, respectively, allowing determinations at the mug l-1 level. Several metal ratios were studied in order to determine the influence of each metal on the determination of the others. The influence of other substances was also studied to determine the potential of the method for speciation analysis studies.