Heavy metals such as lead and cadmium are toxic to environment even in very small concentration. Thus, a sensitive and selective sensor is required to determine such a very low concentration. The purpose this work was to modify the carbon paste electrode using chemically reduced silver nanoparticle (AgNP) and zeolite, and evaluating the performance of the sensors. The modified electrodes were prepared with different proportions of graphite powder, modifier (AgNP and zeolite), and paraffin oil. The bare and modified electrodes were characterized by voltammetry techniques, such as cyclic voltammetry, electrochemical impedance and differential pulse voltammetry in the presence of 10 mM K3Fe(CN)6/ 0.1 M KCl aqueous solution. The effect of deposition potential, deposition time, scan rate and concentration on the peak current voltammetry methods. Voltammograms modified CPE showed an enhancement of the oxidation peak current compared to the bare CPE. This enhancement was clearly observed by increase in electroactive surface area of zeolite. The square root of scan rate was linearly fitted with peak currents and this confirmed that the oxidation reaction at the electrode was controlled by diffusional mass transfer. The optimum deposition potential for Pb(II) and Cd(II) were -0.4 V and -0.7 V respectively. The DPSV result showed that the detection of lower concentration of metal ions were enhanced when the bare electrodes modified with these modifiers. Thus, the surface modification of electrodes improves the detection of heavy metals like lead and cadmium.