Natural zeolite modified carbon paste electrode (NZMCPE) was developed for the voltammetric determination of Cu (11). Copper (11) was selectively preconcentrated, at open circuit, on the NZMCPE. The measurements were carried out by using differential pulse cathodic stripping voltammetry. Linear response to copper (II) was found in the 5.0 x 10(-8) - 5.0 x 10(-6) M (r: 0.9990) concentration range, with a detection limit estimated at 1.5 x 10(-8) M. The multiple determinations (n = 6), following a preconcentration detection-regeneration cycle, shown a relative standard deviation of 2.22% at Cu (II) concentration of 2.0 x 10(-6) M. The developed method was also applied to the determination of copper in two model solutions and two real samples. (C) 2004 Elsevier B.V. All rights reserved.