The binding of lead and zinc ions from aqueous solutions of two different initial concentrations onto natural zeolite in the presence of organic matter has been examined. The Humistar ® solution, which contains humic and fulvic acids, was used to simulate organic matter. It is commercially produced and applied as a soil additive with the aim of better plant growth and yield. Experiments of metal ions removal have been performed with different additions of 10% Humistar ® solution under constant experimental conditions. After equilibration with zeolite and decomposition of the organic matter, lead and zinc ions concentrations have been determined in the liquid phase using the AAS technique. The obtained results show that the amount of bound lead as well as removal efficiency is significantly higher compared to zinc, which is in accordance with previous research. However, the addition of organic matter reduces the amount of binding of lead and zinc as well as removal efficiency, and this reduction is more pronounced with the increase of the addition of organic matter. It can be assumed that there is an inhibition of the binding of metal ions onto zeolite, which is a consequence of several mechanisms of metal ions mass transfer. The first assumption is that metal ions are bound, i.e. sorbed to molecules of humic and fulvic acids, which disables their ion exchange onto zeolite and they remain in the filtrate after equilibration with zeolite. Another assumption is that the molecules of the organic phase are sorbed on the zeolite surface, blocking the active sites available for ion exchange.