Pure NaX-FAU nanoparticles with uniform particle size distribution. High adsorption capacity of NaX for both heavy metals and dyestuff. Capable in removing of heavy metals in real wastewater. Figure A. Variation of the percentage of the metal concentrations in the wastewater after adsorption Purpose: The low adsorption capacity of natural zeolites against heavy metals and dye molecules is to be aimed to increase by the development of environmentally sensitive, simple and low cost nano-sized synthetic zeolites. Theory and Methods: Zeolite nano-particles were produced by classical hydrothermal method at 60˚C for 4 days. The effect of adsorption period, initial pollutant concentrations and adsorbent amount on the zeolite sorption capacity were determined in batch adsorption processes at room temperature using lead, nickel, copper, silver, and methylene blue synthetic aqueous solutions. Adsorption kinetics and thermodynamics were analyzed by Lagergren first and second order models and Langmuir, Freundlich and Sips isotherm expressions, respectively. Results: Results obtained from XRD, SEM-EDX analysis revealed that the synthesized zeolite nanoparticles were pure NaX with ultrafine and uniform particle sizes around 170 nm and Si/Al ratio of 1,24. NaX nanoparticles have high affinities against the contaminating species. As the initial metal and dye concentrations were increased, sorption capacity of the NaX was increased and reached the maximum value of 0.99, 1.33, 2.11, 1.89 and 0.15 mmol /g for the lead, nickel, copper, silver and methylene blue, respectively. Sips model equation successfully described the equilibrium adsorption data of all adsorbates. Conclusion: It was concluded that the removal of cations was mainly occurred based on the ion-exchange mechanism. Higher affinity relative to other adsorbents indicates NaX nanoparticles a strong candidate in wastewater treatment processes involving the removal of heavy metals and dyestuff.