Chemically modified carbon paste electrodes incorporated with zeolite molecular sieves were constructed as sensor electrodes for voltammetric determination of trace copper in aqueous solution. Square wave voltammetric techniques were used to quantify Cu(II) in aqueous solution. The copper response was characterized with respect to electrode composition, cleaning solution, Cu(II) concentration, preconcentration time, pH, and other variables. The peak current was found to be linearly related to the concentration of Cu(II) in the range of 0.3-1.0 mg l(-1) with a correlation coefficient of 0.9992. The electrodes were electrochemically sensitive to copper in ammonia buffer solution with a detection limit of 0.074 mg l(-1).