This study investigates the electrochemical detection of cadmium (Cd²⁺) and lead (Pb²⁺) ions in water using MOF-5/PANI composites. Six different composites of MOF-5 and polyaniline (PANI) were prepared with varying mass ratios of MOF-5 and PANI. The composites were evaluated for their electrochemical performance, and their behavior was compared with individual components, PANI-ES and PANI-EB. The materials were characterized using Raman spectroscopy, scanning electron microscopy (SEM), and dynamic light scattering (DLS). All composites exhibited high electrocatalytic activity for the oxidation of Cd and Pb ions. The MOF/EB-1 composite, containing 71.0 wt.% MOF-5, showed the highest oxidation currents during both individual and simultaneous detection of the heavy metals. The MOF/EB-1 composite also demonstrated low limits of detection (LOD) of 0.077 ppm for Cd²⁺ and 0.033 ppm for Pb²⁺. Voltammograms of the MOF/EB-1 composite in real water samples from the Danube River showed well-defined peaks for the oxidation of Cd and Pb ions, indicating its potential as an electrochemical sensor for heavy metal detection in water samples.This study investigates the electrochemical detection of cadmium (Cd²⁺) and lead (Pb²⁺) ions in water using MOF-5/PANI composites. Six different composites of MOF-5 and polyaniline (PANI) were prepared with varying mass ratios of MOF-5 and PANI. The composites were evaluated for their electrochemical performance, and their behavior was compared with individual components, PANI-ES and PANI-EB. The materials were characterized using Raman spectroscopy, scanning electron microscopy (SEM), and dynamic light scattering (DLS). All composites exhibited high electrocatalytic activity for the oxidation of Cd and Pb ions. The MOF/EB-1 composite, containing 71.0 wt.% MOF-5, showed the highest oxidation currents during both individual and simultaneous detection of the heavy metals. The MOF/EB-1 composite also demonstrated low limits of detection (LOD) of 0.077 ppm for Cd²⁺ and 0.033 ppm for Pb²⁺. Voltammograms of the MOF/EB-1 composite in real water samples from the Danube River showed well-defined peaks for the oxidation of Cd and Pb ions, indicating its potential as an electrochemical sensor for heavy metal detection in water samples.